Bioexcel Webinar #95: DynaPIN: A Tool for Characterizing Dynamic Protein Interfaces
Watch on YouTubeVideo summary
The webinar introduces DynaPIN, an innovative Python-based tool designed to characterize dynamic protein interfaces through time-resolved analysis of molecular dynamics trajectories. Developed by Dr. Esra Karaka and Berrin Yılmaz from the Izmir Biomedicine and Genome Center in collaboration with French partners, this project addresses a critical gap in structural biology where static structure analysis is insufficient for understanding biological function. With the advent of AlphaFold generating millions of high-quality models, researchers now have abundant data to interpret; however, analyzing how these interfaces behave dynamically has been lacking. DynaPIN fills this void by enabling systematic simulations and analyses that link microscopic atomic observations to macroscopic biological phenomena, specifically focusing on interface stability, specificity, and transient interactions over time scales as short as 100 nanoseconds.
The tool is built upon a standardized framework comprising three core modules: quality control, residue-based analysis, and interaction-based profiling. To ensure accurate identification of dynamic interfaces across varying simulation times, the developers adopted an elegant definition classifying interface residues into support, rim, and core categories based on solvent accessibility changes. By default, DynaPIN considers a residue part of the dynamic interface if it remains in contact for at least 50% of the trajectory duration, though this threshold is customizable to accommodate "fuzzy" interfaces or specific research needs. The software integrates various computational tools such as FreeSASA and FoldX within a single pipeline to calculate metrics like RMSD, electrostatic energies per residue, hydrogen bonds, and hydrophobic contacts, ultimately generating publication-ready figures and raw CSV data for further statistical analysis or machine learning applications.
A live demonstration showcased the tool's user-friendly workflow via both command-line interface and interactive Jupyter notebooks, highlighting its ability to process diverse inputs including PDB ensembles and DCD trajectories from major simulation engines like GROMACS. The presentation emphasized that while DynaPIN currently utilizes FoldX for rapid energetic calculations due to licensing constraints on other tools, the underlying architecture is general enough to support protein-nucleic acid interfaces in future updates pending further testing. Additionally, the team has established a large-scale benchmark dataset called Dynabench, derived from Docking Benchmark 5.5, which provides curated trajectories and standardized analysis outputs to foster comparability across different research groups and facilitate collective learning in the field of biomolecular dynamics.
In conclusion, DynaPIN represents a significant step forward in structural biology by providing an accessible, open-source solution for dissecting the complex dynamics of protein interfaces that static models cannot capture. The presenters highlighted their commitment to community collaboration through shared data resources like Dynabench and invited researchers to test the tool on various systems, including those involving nucleic acids, while promising future updates based on user feedback. As computational power increases and more high-quality structural predictions become available, tools like DynaPIN will be essential for interpreting how biological interfaces form, stabilize, and function dynamically, bridging the gap between theoretical simulations and experimental observations in a standardized manner.
Read the full video transcript
So, welcome to this Bio Excel webinar.
Today's topic is Dynapin, a tool for
characterizing dynamic protein
interfaces.
Uh just so you know this webinar is
being recorded and we will also upload
uh a copy of this later to the Bioexl
YouTube channel.
Uh during the presentation you can ask
questions with the Q&A uh function.
Uh the questions will be answered after
the presentations.
Uh if you still have any questions after
the webinar,
you can ask them in the Bio Excel
forums.
There should be a topic for this webinar
there.
And today's presenters,
Etsy is a computational structural
biologist specializing in structural
modeling and biomolecular dynamics.
Excuse me.
She completed her PhD at Utrex
University under the supervision of
professor Alexander Bonman where she
advanced hadock. She then conducted her
post-doal research at EMBL H Highleberg
with Professor Teresa Carlo Mango and
Professor
O or Soloya Barabas uh developing M3, a
protein complex modeling tool capable of
handling 20 molecules using sparse
experimental data. Uh in 2017, uh Dr.
Karaka established the computational
structural biology lab at Ismir biio
medicine and genome center and joined
dou uh ail university. Sorry if I
destroy any names here. Her lab develops
classical and AIdriven approaches to
model biomolecular interactions and
their dynamics.
She received an EMBO installation grant
and uh was also the first assessor from
Turkey in CASP 14 and CASP 15 for the
assembly prediction rounds. Our lab's
first online tool, Proton, a
structurebased web server for designing
inter facial mutations, gained
significant attention from the
scientific community with 50,000 users
per year worldwide.
Uh Bertin is a computational structural
biologist specialized in molecular
dynamics simulations and biomolecular
interface analysis. She completed her
PhD at the Ismir biio medicine and
genome center and douut
alil university I'm sorry I'm so sorry
under the supervision of Dr. Eski Karaka
as a post-doal researcher at IBG
uh Bin is currently working on the
development of Dynapin a Python-based
package for time resolved
characterization of protein protein
interfaces. She's also one of the
contributors of Dynabbench, a large
scale molecular dynamics data set
designed to capture interface dynamics
beyond statistic reference structures.
That was a mouthful. I'm sorry.
But uh over to you now. So I'll stop
sharing and hand over to you.
>> Great. Thank you, Otto. Uh and no
worries. It was uh all perfect. Uh so
our institutions names are a bit
difficult to pronounce.
Um
uh anyway so um I would like to thank
first the Bioexile team for giving us
the opportunity to present our latest
work. Uh and also uh I would like to
thank Otto and Lakshman to uh host us
today. Also uh thanks I also would like
to thank everyone who is here today with
us. Um last time I fell ill and that's
why we couldn't um uh we couldn't um
make the webinar. Uh but hopefully it
will be worth it for you to to wait.
Uh so today I'll be presenting the
concept of uh the tool that we recently
developed to characterize dynamic
protein interfaces and I'll explain what
I mean by this and then after my
presentation bin will have a
demonstration of the tool uh so that the
ones who would like to give it a try can
have an opportunity to have an overview
of how to run the tool on their own
resources.
Um so um we all know that we are living
in very interesting times. Um currently
uh modeling protein interactions
um has been much easier compared to in
the previous decades. um firstly because
uh we have alpha faults and second we
have a decades long accumulated
knowledge on uh protein interaction
prediction.
So what was achieved by alpha for
monomer modeling uh was also um
reflected into multimer modeling.
uh and currently especially if we talk
about DRS as long as you have a good
multiple sequence alignment for your
partners uh it's very likely that you'll
end up having a a good interaction model
as an outcome of as an outcome of using
alpha fold and different versions of
alphault um which is something uh uh
impressive if you are curious which
tools which alpha fold uh tools to use
for which type of uh uh modeling h you
can try to mod you can try to follow the
previous papers uh analysis community
analysis papers published by Casper and
Capri uh one of which is listed here
uh as an outcome of this uh great
advancement uh now we have uh we have so
many models uh within our reach that are
waiting for us uh to interpret them. Uh
so for some time we had uh deposited
models on monomers and their uh domains
but just recently uh uh less than a
month ago uh EBI extended their data
sets by including several highquality
homr and heterr structures. Um and
actually it's not several but millions
of structures. uh which means like
actually now it's a good time uh to say
okay uh when we have a confident
prediction and we have many confident
predictions now uh maybe it's time to
move to a systematic analysis of how
biological interfaces are formed and how
are they are staying at the dynamics
level and this is uh this sole aim of
the project of the uh framework that we
are presenting today uh we started Ed um
the idea with the idea that um okay
having interface analysis on static
structures is is a great tool and it's
very fast and we can do many things with
it but now with the availability of so
many models as well as availability of
uh high high performance computing
centers now we should also start doing
um micro dynamic simulations
of the interfaces I mean the whole
systems in the end but focusing on the
interfaces.
There has been um a quite a number of uh
efforts together MD data sets or having
more like collective analysis on uh
several uh um several MD systems. Uh but
somehow the um analysis and the uh
trajectory generation that are
specifically focusing on the interface
set has been missing and uh this has
been on our list. So this gap has been
on our to-do list already for a while
especially since in um four papers
already in the last couple of years. We
have seen that if we simulate our
systems and if we compare the interface
dynamics at the atomistic level, we
compare the types of interactions, if
you compare the types of confirmational
changes happening across the interfaces,
we can actually very nicely and
elegantly link um very tiny microscopic
observations to the microscopic
biological ones.
So this uh we started uh with the idea
started all in 2021 with a with a
paralog system where three protein
partners are getting together and they
are structurally very similar but they
had a different selectivity. So at first
we we performed simulations on all
systems and also on negative binders as
well to understand what drives the
selective binding and after this uh we
uh actually extended the type of
analysis and then the content and
applied on other systems as well
including protein nucleic acid systems
or even systems as large as the
nucleosome. So after having these
observations we became very confident um
that um actually um in terms of the
analysis that we performed uh should be
uh standardized should be released but
it should be also shown that it can be
applied in a general manner and for this
we were very lucky because we
encountered Sophia and Shantel from IBPC
CNS Paris. Uh so they had also similar
intentions.
uh together uh with Bartin and me myself
um as an outcome uh we decided to write
a joint project. There was a call
between uh France, a bilateral call
between France and Turkey and then we
got the project and as an outcome we um
we formed a a beautiful collaboration uh
where uh several MD data sets are
generated by the France team and the
analysis package and the analysis of the
trajectories are performed by the
Turkish team. uh so I'll briefly uh uh
introduce Dynaben to you which is the
benchmark dynamic benchmark that I that
I just mentioned and then I'll discuss
DAPIN in a bit more detail and then
afterwards I will I'll leave the floor
to Barin so that uh she will uh uh she
can present the contents of our package.
Okay. So at first Dina Dina bench uh
this is actually the first systematic MD
benchmark that is specifically focused
on the interfaces. Of course what we do
is we perform standard classical
unbiased molecular dynamics. So there's
nothing specific to interfaces at this
point but we selected a data set that
are specifically curated to understand
different interactions and this is
called docking benchmark 5.5. So earlier
pre-alpha fault times meaning pre-AII
times uh when someone was developing a
new model to new um computational tool
to predict protein interactions they
always had to benchmark them on docking
benchmark 5. So there was no training
the methods were mostly physics based
that's why it was totally okay but now
together with the reduce of alpha fold
as this benchmark is also a bit old um
having this benchmark as a structure
prediction benchmark became obsolete but
it's still a very nicely curated and
nicely classified data set because
inside we have enzyme inhibitors antibi
antigens they are all um functionally
annotated they all have bound and
unbound structures So it's a really nice
resource to actually turn into an MD
data set, MD benchmark. As an outcome,
our French partners uh what they did was
they took 200 complexes from this
benchmark
and simulated uh them each of them three
times for 100 nconds. In an earlier work
of theirs which actually which is the
work that kind of united us in an
earlier work of theirs they showed that
um 100 nanconds uh standard should be
okay to understand the interface
dynamics. Okay, we know that it's a
short time but here as I was mentioning
our aim is to understand which
interactions are stable, which
interactions are specific, which
interactions are transient and how is
the interface staying consistent across
100 nconds. What they observed in their
in a previous paper of theirs was uh
even in the first 30 40 nanconds you
observe if there's an interfacial change
and that's why uh this time uh we hope
should be enough. Uh so all our data
sets and trajectories are online you can
download them through uh this uh uh web
link from this uh associated to uh CNRS.
Um and basically you can also uh run use
them for any type of analysis or
training uh you want to have.
Um and as the second part the second
part is the part where we are mo mostly
involved in together with Bin. Uh we are
concentrated on developing and
standardized analysis package. uh so one
thing that was puzzling us when we were
uh working in these previous biological
examples that I was mentioning where we
were performing comparative analysis to
understand which interface behaves
differently than others uh we used
several different types of analysis and
in the end by checking the literature as
well we came up with a with a tool set
analysis set that we think like should
be standardly performed to understand
the function of an interface uh and
together with this we also have the uh
we also have the uh aim to have uh to
provide a standardized uh output for the
users so that at least uh from this
point and on MD results will be
comparable to each other because as we
all know the major problem in the MD
analysis field is that everybody is
using their own type of analysis which
will help them to uncover the biological
function they are researching. Um so I
think for also developing any type of
machine learning or AI approach we need
the standardization and collectively
gathering all these we hope that our
dynamics uh dynamical dynamics analysis
package which is focusing on
characterizing interfaces in a
standardized manner hopefully we'll find
a nice place uh for itself in the
community.
Uh so coming to the architecture of our
uh um of our tool uh that we called
dynapin because basically we are
analyzing the changing interactions
across an interface over the time course
of a trajectory. Um we in principle can
get uh the input trajectory from all
major uh simulation uh engines. Uh but
you can also input uh PDB and sample.
For example, you can also run uh NMR
structures uh with this pipeline
or you can mix models from different
tools and then uh just feed them uh to
the um to the analysis tool. Um the
trajectory or the PDB should be
accompanied with a topology file which
could be a PSF or uh PDB. Uh there the
program is going to read the chain ids
etc all the properties. So it's
important uh to remember of course that
the topology and trajectory files should
have matching atom content with matching
chain content chain content and we have
different types of configurations. If
you don't touch anything by default it's
the program is going to run everything
that we are just going to describe but
there's also an option to run everything
individually as a separate analysis file
analysis um command. Uh so the so in the
core of the dynapin we have three
modules uh which is quality control okay
everyone runs quality control anyway so
this is the most standardized part of MD
analysis mentality but then we also
offer two other uh modules uh one is
residue based and the other one is
interaction based and I'm going to come
to them in the up in the uh upcoming
slides
and when the all the analysis are
finished uh at the end we provide uh raw
data in CSV format that is an outcome of
uh all the calculations and we also
generate uh automatically publication
ready figures uh that are presenting the
most interface-based
um uh uh features that the user we hope
would like to have.
Um so when we since we are focused on
understanding how the interfaces are
changing over time, how the properties
are changing over time, uh we first had
to come up with a new interface
definition for this type of analysis
because um the first uh frame in your
trajectory is different compared to the
last and you of course will have
different interface residues in both. So
the first point for us to decide was
okay first of all which interface
definition we are going to use because
there are different interface
definitions we wanted someone to be fast
but also accurate and that's why we
resorted to the um famous uh definition
uh from Emanuel Levi which is um a bit
old right now but it's uh really nice
and elegant. Uh so it's the it's
basically classifies pines for the
interface amino acids based on the
solvent accessibility ch accessibility
change of the residues upon complexation
and then based on the solvent
accessibility uh rate of change. It
classifies the interface into three
categories as support core and rim. Core
is at the center super hydrophobic uh
rim is at the outer ramps. For example,
this is the place where you would find
the salt bridges that are uh stabilizing
the uh the edges of your interface and
uh support is in between these two.
uh and then uh what we also do is we
calculate this interface residues over
over the whole trajectory and we say by
default if a residue is to be found at
the interface for the 50% of the
simulation time then this this amino
acid is considered to be a part of the
dynamic interface. Um the user can
change uh this uh percentage it's not
fixed. Uh but from our own internal test
50 turn out to be a good number.
So after defining this dynamic uh
interface throughout the whole
trajectory or throughout your ensemble
here is what we output at one go. So we
have as quality control RMSD RMSF radius
of generation and together with this we
also have capri metrics. So for the
people who are familiar to Capri, DOQ is
a very well-known metric. But for the
people who don't know this yet, DOQ is a
metric that is composed of interfas,
ligament MSD and fraction of native
contacts and it actually measures how
the complex changes from one state to
the other and usually it's being used to
assess uh protein interaction models but
in this instance we use them to analyze
the trajectory. Uh then as a second
option we have this second module we
have the residuebased module. Here we
have all the relative solvent
accessibilities of all amino acids. Uh
we have the dynamic interfaces and their
assignments either uh being at the core
rim or the uh support. uh we have the
secondary structure assignments so that
for example the user can see whether
there's any secondary structure change
across the interface and we also nicely
calculate electrostatics and wonder
energies on a per residue basis. This
was something that we were missing and
we wanted to have this for our previous
uh analysis in our previous projects.
That's why we thought that it would be
helpful to add this as well. And as a
third module we have the non-covalent
interaction module and we believe that
this is the part um this would be maybe
the most useful among all I mean all the
uh options are useful but this we found
to be most useful when we are uh trying
to understand the impact of the
interface on the function of the complex
and here we provide at one go the uh
intra interchain hydrogen bonds all at
the atomistic level so bridges and
hydrophobic context.
Um so I'll just briefly um demonstrate a
couple of analysis on a docking
benchmark case that we have. Uh and then
with this I'll I'll be finished with my
part. Uh so the docking benchmark
classifies the targets classifies the
complexes according to their binding
types as well as according to the
confirmational change uh the monomers
are um the monomers are experiencing
upon binding. And here we demonstrate a
case where the uh where the complex was
characterized at difficult meaning like
these two monomers are experiencing
large scale confirmational change upon
binding. And since this is a published
structure, we also know we also could
refer to its paper and from the paper we
know that there is a very specific salt
bridge uh which is helping the complex
uh to get stabilized uh across its
interface. So uh we run all the analysis
at one go that I just mentioned and I'm
only going to present to you uh a couple
of analysis that we think should be
useful for you to see. Um and here you
see the output uh that we run to obtain
all the analysis that I'm just going to
mention. Uh so the file is coming from
DAB and in Dynaben the trajectories are
in the dry trajectories are in the DCD
format. So that's why we are inputting a
DCD file. uh and then we are getting out
all analysis and all plots and we choose
a resolution uh as 10 which is like
analyze or pull uh every coordinate in
every 10 steps. uh so what we observed
for this complex for the duration of uh
uh time scale was here we don't refer
time uh on the x-axis because uh we know
that uh people might be giving just a
part of their trajectories or they might
be giving a pdb ensemble that's why we
uh always uh report things on a per
frame basis so what we observed over
here is that from the 200 frame and on
the trajectory even from earlier on the
trajectories is uh interface RMSD is
very stable meaning like the interface
is very stable as soon as you pass the
equilibration the interface is behaving
the same and here you see the uh root
mean square fluctuations based on
different chains chain A and chain B and
the red dots represents the interface
aminosis the dynamic uh interphase
aminosis that are mapped on this plot
and here you also see that the RMSFs of
the interphase aminosis uh quite A
number of them are below one extra and
then a few of them are between one and
two which also indicates uh which also
indicates a rather stable uh interface.
Uh then uh we pulled another uh figure
uh which is the electrostatic energy um
analysis. In this type of analysis, what
we provide with is that uh we um um
calculate per residue um electrostatic
electrostatic energy throughout the
whole frames and then we plot a box
plot. We plot the distribution of the
energies that we observed as an outcome
of this. For example, what we can see
that there is this lien uh 30 lizen 32.
So there is a typo here. Sorry. Lizen 32
which is uh very significantly
contributing to the inter
have um across the surface and you can
also see you can also see here that um
uh we don't have many interface residues
because these are all the uh inter we
don't have many interface residues
contributing to the electrostatics let's
say uh because uh we have uh the plots
only for the ones for which the
electrostatics energy is calculated
and this is also support bridges that we
observe throughout the simulation and
this kind of calculates our observ the
observation that is coming from
literature. So this is rather a proof of
concept case in our um uh preprint. Uh
we have uh more um deeper examples. I
didn't want to present them here uh just
to be able to concentrate on the package
in
instead of its biological applications.
But we have better examples on our
preprint if you are curious to have
our preprint also raw data looks like.
So these are all uh nicely organized CSV
files uh that we are outputting. So if
you don't like our figures uh we think
that they are nice but you might not
like them you can generate your own
figures as well. So this is why we are
providing the raw data as well also
hopefully we are providing the raw data
so that this type of data can be
deposited together with the papers uh
when uh people submit uh their MD
trajectories uh to a journal.
Okay with this uh my part is done. Uh so
Bin is the one who is the who developed
the analysis. Um so she is the uh uh
main developer. We had support from uh
other earlier lab members. Uh but in the
end she is the one who made it uh so
elegant and that's why I think I already
talked enough. So Vin the floor is
yours. Please um continue uh with the
rest.
>> Okay. Hello everyone again and thank you
very much Esgie for that uh overview and
the uh theoretical background of the
motivation of the dynapin and now um I
would like to uh take you all from the
to the practice and firstly I would like
to share my screen
okay um first I will briefly walk
through to the uh GitHub repository to
show how Dynapin is uh structured, how
it's installed and how it's used and
then I will run a live example uh on my
computer.
Uh as you can see here on our repository
page, we have a structured uh
documentation to be as user friendly as
possible. Uh let's quickly go through to
the main sections.
Um as uh as we mentioned, Dynapin
provides uh through frame by frame uh
analysis of molecular dynamics
trajectories and it automatically
extracts these dynamic interface metrics
as we can see here. Uh now um
in the K features uh I can say that
Dynapin is organized around three main
modules uh quality control, residue
based and interaction based. So uh in
the overall uh the workflow is uh built
um three layers. First we assess the
global behavior of the system. Then we
characterize the interface uh residues
um over time and finally we resolve
these into the specific interaction
patterns.
Moving down to the system architecture.
Dynapin is built as modular uh Python
framework. We integrated commonly used
uh tools such as MD analysis um PDB
tools for trajectory handling uh free
SUSA for uh um calculating uh solvent
accessible surface area foldics for
energetic analysis
for secondary structure assignment and
interphase for the interaction pro
profiling uh within the same pipeline.
Uh this means that uh users do not need
to manage these components separately.
Instead they can uh run a single
workflow and obtain results uh in a
standard design uh output structure with
uh tables and figures.
And in the system requirements section
we summarize the basic setup uh needed
to run the Dynapin. Uh, Dynapin supports
um Linux and MacOss operating systems.
Uh, Windows users also uh use Dynapin
with VSSL. Uh, for installation uh users
uh need Git uh cond to the Anaconda or
Minionda and Python version 3.10 or
higher.
Um as a note uh here we specifically
highlighted the foldex uh although uh
all the packets used by dynamin
installed your computer automatically
with cond environment and foldex is an
exception due to the due to the le
licensing restrictions. If you want to
run uh energetic analysis uh you need to
download foldics separately and uh
provide uh its path as a argument.
And here uh you can see the installation
uh section. The installation is
intentionally simple. Uh first the
repository is cloned, then the cond
environment is created and finally it's
activated. So with just few comments,
Dynapin is ready to use. Um you just
need to copy and paste these comments on
your terminal.
Uh once installed uh how do you use it?
Um
this section uh shows the main usage
logic of Dynapin. We offer two main
workflows. The first option is the
command line interface.
Um,
Dynap can be run directly through the
command line interface with a single
comment. As you can see here, uh, these
are the example commands for both PDB
trajectories or PDB ensembles and a DCD
trajectories uh with a topology file.
And here is the other arguments. Uh just
below the main uh command line arguments
are listed. Uh very briefly these
arguments uh control three things. The
input files uh the analysis setup uh and
the output location. Um I will also go
through these com uh arguments in my
demonstration.
So uh this second option is the
um interactive APA API workflow.
Uh today I will show you in the
demonstration part how you can see uh
how you can use the uh provided Jupyter
notebook uh and interactive API
workflow.
Yes. Uh here uh here uh in the output
file section uh this is the output file
organization.
Uh the results are written into
structured uh tables and figures uh
directories and the outputs from the
quality control residue based and
interaction based analysis are clearly
separated and systematically named here.
Okay, then um I will now switch to the
short demonstration
with a Jupyter notebook. I uh have
already activated my Dynapin cond
environment and my uh
uh let me show yes uh and my input
trajectory and topology files are
located in my working directory. This is
the my um Jupyter notebook also. Uh
this notebook is um exactly the same
with the provided one uh in our GitHub
GitHub repository.
In the first step,
I run this cell. Uh we simply import the
core uh dynapin modules.
Uh this step two is crucial because this
is where we define uh all of our inputs
uh parameters. Uh let me quickly go
through the arguments. Uh
we are setting here.
Uh trajectory file and topology file. Uh
these are our inputs. Uh today I am
providing a DCD trajectory and my
topology file here. Uh if you are using
um uh PDB ensemble uh you can set this
topology file to none.
Um
this job name dictates the name of the
output directory where uh all our tables
and figures will be safely stored.
Uh this stride value for this demo uh I
am intentionally using a relatively high
uh stride value here. Uh let me increase
it to 200.
Um the reason is simply to keep the run
short enough for this webinar instead of
analyzing uh every single frame but you
can keep this as one then you can
analyze all of the frames in your um
trajectory. Uh split models um argument
is uh when we set this true dynapin uh
will produce splitted models of your
trajectory.
Um I have set the chains uh argument to
none uh to let Dynapin auto detect the
interacting chains. But uh you could
easily specify this something like um A
and B. Uh dynopin uh allows to analyze
dimer complexes. So if you have more
than two chains in your complex, the
chain selection allows uh you to
restrict the analysis um to selected two
chains.
Uh threshold is the cutoff value uh
cutff percentage of identifying dynamic
interface residues as ESG mentioned in
her presentation. Uh I leave it at the
default 50%. Uh this means that if a
residue stays at the interface layer um
in other words support rim and core uh
more than 50% of the simulation dynapin
defines this residue uh as a dynamic
interface residue
and here lastly uh I defined here the
foldics executable pet
uh as I said uh if you don't want if you
don't have the licensed fodex executable
or do not wish to run energetic
analysis. Uh you can set this none.
Now I'm running this cell.
Yes, in the step three uh before running
the heavy calculations uh the notebook
allows us to do a quick senate check
using ngl wheel. I run this cell. Uh,
and we can actually visualize our loaded
trajectory here
to ensure the um
the chains look correct and your
trajectory is uh okay.
Then in this step four I initialize the
dynapin uh engine.
The setup has completed.
Then now I am running the quality
control analysis here.
It's already completed.
And here I run the residue based
analysis.
This is where Dynap calculates uh
solvent accessible surface area um
energetic calculations etc.
And uh yes
once that finished the notebook provides
a really cool um interactive uh substep.
Let me run this cell. Yes,
we can visualize just the dynamic
interface residues here, the ones that
scored uh above our threshold value. Uh
you can see the overall protein in
transparent uh cartoon format while the
dynamic interface residues are
highlighted as a solid sticks.
Moving
to the step seven,
the uh interaction based analysis that
we execute
This may take a while.
Okay, this is completed.
Uh now that all of our calculations are
completed and the CSV files uh is
written to the tables folder. uh as um
as we already showed uh the overview of
this table and so we initialize the
plotter class here and I run this cell.
The plots are generating.
Here you can see a overview of the
generated um plots.
But uh as a last step
uh we have a interactive uh result
viewer
and to visualize all the plots DAPIN
generated like um
interaction frequencies
as a bar plot time evolution of the do Q
score of native contacts
and
RMSD,
RMSF
and secondary structure uh assignments
and the
energy distribution of the um dynamic
interface residues.
Uh before I wrap up this demo, I want to
quickly
show you the um
how Dynapin organized all these data.
This is the um folder that Dynapin
created
and inside here we can see the two main
subdirectories figures and tables. Uh in
figures you can see all the high
resolution um plots here
like this.
And the other uh directory is tables. Uh
here you can uh also see the CSV files.
If you don't um use to uh Detin figures
and um if you want to do your own custom
plotting or the statistical analysis
later uh you can use these uh CSV files
directly.
Um I want to also point out these uh
JSON files. These JSON files keep your
um run parameters
uh like this uh to reproduce your uh
dynapin run. Again
uh finally we also have some
intermediate data. Uh this is the models
uh zip file. Uh this uh keeps the um the
the
intermediate frames uh of your
trajectory and the uh this fixed
standard design PDB uh contains the uh
standard design uh ensemble of your
trajectory.
Uh and that's it. uh from route
trajectory to organized publication
ready and uh ready data and visuals uh
all in just in a few steps.
Uh
okay, that's it.
Thank you for the for the demonstration.
Yes, please auto.
>> Yeah. Could I have the screen? Yes.
So it's time for Q&A questions. We have
two of them already here.
So first one is thank you for the talk.
This is great work. Fuzzy interfaces
exist that do not respect the 50%
threshold of contact time. Uh what do
you recommend when using Dynapin for
fuzzy interface analysis? Any caveats we
should be wary of when running the code?
Uh so
I I can answer this first of all the
nice words. Um all the interfaces uh
that are being tested under the
framework of um DAB as well as our
previous interaction analysis the papers
that I presented to you none of them
contains uh contains a puzzy interface.
uh so from my personal experience
um I I can't tell a number uh but we've
thought of such type of scenarios and
considering this we change the cutoff we
made the cutoff a variable so you can
input your own cutoff uh but what I
could advise to uh what I could advise
for you would be to um run it with
different uh thresholds and until you
think like the threshold is small enough
to produce understandable results
because uh um depending on the uh
threshold obviously the amount of
interface residues that will be selected
uh will differ. Uh so this is as much as
I can say at the moment. I hope that
this answers your question.
>> Okay. Then next question is how do you
analyze the residue residue decompos
decomposition energies? Is it based on
mmgbsa or mmmpsa?
>> Uh so here uh let me answer this as well
as bin mentioned h we use foldex. Uh the
main reason why we use foldex is that uh
it's uh it's a fast algorithm. It's very
fast. So if we uh if we were to resort
uh more uh accurate energy com
calculations like MMPBSA
uh then the calculation would have
lasted quite long. Uh but since uh the
trajectory is already chunked into uh
pieces uh by the uh dynamin approach,
one could also use uh these um uh frames
um with other energy analysis tools if
one has the resources for it. But here
are choices based on the speed.
>> Okay, there are no more questions.
All right, there is actually one more
right now.
Uh, thank you for a nice demo. Do you
plan to extend this to protein nucleic
acid interfaces? Uh, and the second
question regarding the MD benchmark data
set on protein protein interfaces, do
you know how how do AF generated
ensembles compared to this benchmark?
Thank you.
>> Okay, thanks uh for these nice
questions. So first of all
maybe uh Bin claims that you can already
use it for proteinic acid interactions
right there's nothing against it right
Barian
>> yes yes but I couldn't test it enough
for protein nucleic interactions
>> but uh in the current version of the
dynapin you should be able to uh
calculate the proteinucle clear cast
complexes.
>> Mhm. So the we actually uh
but how Bin framed the analysis package
is that everything is written in a
general way so that one could also use
it for different types of molecules but
we didn't want to we don't want to
adverize
it like the dynaben uh benchmark uh but
in principle you can try to use it for
uh protein nucleic acid interface phases
and it would be great if you uh uh have
a fe if you if you want to try and then
you give us a feedback we would much
appreciate this and regarding this
second point so we actually have another
project running uh for to answer your
question uh but we are still at the
preliminary stage so I cannot um answer
your question at the moment but we are
curious about this as well hopefully
soon uh we'll have some preliminary data
to present on the suspect too.
>> Okay, no more questions it seems.
Uh we still have time so we can if
there's uh one more question popping up,
we can get back to it quickly later.
Meanwhile, I will take this opportunity
to show us the upcoming webinars.
Uh
there will be one on 12th of May again
driving forces in biomolecular
condensates from atomistic simulations
of model peptides.
And then later in May on the 26th there
will be con I need better glasses for
this confir confirmational ensembles of
intric intrically
intrinsically disordered regions and
proteins.
Oh and uh one more
shout out.
There's a bioxal conference coming up in
Berno in September and there's still
it's still open for registration.
Uh abstract deadline 1st of May. So I'll
leave this up for a moment so you can
scan the QR code if you're interested.
Thank you everyone for joining us.
>> Thanks a lot.