Tag Archives: Python

Mapping derivative compounds to parent hits

Whereas it is easy to say in a paper “Given the HT-Sequential-ITC results, 42 led to 113, a substituted decahydro-2,6-methanocyclopropa[f]indene”, it is frequently rather trickier algorithmically figure out which atoms map to which. In Fragmenstein, for the placement route, for example, a lot goes on behind the scenes, yet for some cases human provided mapping may be required. Here I discuss how to get the mapping from Fragmenstein and what goes on behind the scenes.

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Using JAX and Haiku to build a Graph Neural Network


JAX

Last year, I had an opportunity to delve into the world of JAX whilst working at InstaDeep. My first blopig post seems like an ideal time to share some of that knowledge. JAX is an experimental Python library created by Google’s DeepMind for applying accelerated differentiation. JAX can be used to differentiate functions written in NumPy or native Python, just-in-time compile and execute functions on GPUs and TPUs with XLA, and mini-batch repetitious functions with vectorization. Collectively, these qualities place JAX as an ideal candidate for accelerated deep learning research [1].

JAX is inspired by the NumPy API, making usage very familiar for any Python user who has already worked with NumPy [2]. However, unlike NumPy, JAX arrays are immutable; once they are assigned in memory they cannot be changed. As such, JAX includes specific syntax for index manipulation. In the code below, we create a JAX array and change the 1^{st} element to a 4:

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Under-rated or overlooked, these libraries might be helpful.

Discovering a library that massively simplifies the exact thing you just did right after you’ve finished doing the thing you needed to do has to be one of the top 14 worst things about writing code. You might think it’s a part of the life we’ve all chosen, but it doesn’t have to be. Beyond the popular libraries you already know lies a treasure trove of under appreciated packages waiting to be wielded. Being the saint I am, I’ve scoured the depths of pypi.org to find some underrated and hopefully useful packages to make your life a little easier.

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Working with PDB Structures in Pandas

Pandas is one of my favourite data analysis tools working in Python! The data frames offer a lot of power and organization to any data analysis task. Here at OPIG we work with a lot of protein structure data coming from PDB files. In the following article I will go through an example of how I use pandas data frames to analyze PDB data.

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Taking Equivariance in deep learning for a spin?

I recently went to Sheh Zaidi‘s brilliant introduction to Equivariance and Spherical Harmonics and I thought it would be useful to cement my understanding of it with a practical example. In this blog post I’m going to start with serotonin in two coordinate frames, and build a small equivariant neural network that featurises it.

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Finding and testing a reaction SMARTS pattern for any reaction

Have you ever needed to find a reaction SMARTS pattern for a certain reaction but don’t have it already written out? Do you have a reaction SMARTS pattern but need to test it on a set of reactants and products to make sure it transforms them correctly and doesn’t allow for odd reactants to work? I recently did and I spent some time developing functions that can:

  1. Generate a reaction SMARTS for a reaction given two reactants, a product, and a reaction name.
  2. Check the reaction SMARTS on a list of reactants and products that have the same reaction name.
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Let your library design blosum

During the lead optimisation stage of the drug discovery pipeline, we might wish to make mutations to an initially identified binding antibody to improve properties such as developability, immunogenicity, and affinity.

There are many ways we could go about suggesting these mutations including using Large Language Models e.g. ESM and AbLang, or Inverse Folding methods e.g. ProteinMPNN and AntiFold. However, some of our recent work (soon to be pre-printed) has shown that classical non-Machine Learning approaches, such as BLOSUM, could also be worth considering at this stage.

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The workings of Fragmenstein’s RDKit neighbour-aware minimisation

Fragmenstein is a Python module that combine hits or position a derivative following given templates by being very strict in obeying them. This is done by creating a “monster”, a compound that has the atomic positions of the templates, which then reanimated by very strict energy minimisation. This is done in two steps, first in RDKit with an extracted frozen neighbourhood and then in PyRosetta within a flexible protein. The mapping for both combinations and placements are complicated, but I will focus here on a particular step the minimisation, primarily in answer to an enquiry, namely how does the RDKit minimisation work.

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What the heck are TPUs?

I recently became curious about TPUs, a specialised hardware for training Machine- and Deep-Learning models, where TPU stands for Tensor Processing Unit. This fancy chip can provide very high gains for anyone aiming to perform really massive parallelisation of AI tasks such as training, fine-tuning, and inference.

In this blog post, I will touch on what a TPU is, why it could be useful for AI applications when compared to GPUs and briefly discuss associated opportunity costs.

What’s a TPU?

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Deploying a Flask app part I: the gunicorn WSGI server

Last year I wrote a post about deploying Flask apps with Apache/mod_wsgi when your app’s dependencies are installed in a conda environment. The year before, in the dark times, I wrote a post about the black magic invocations required to get multiple apps running stably using mod_wsgi. I’ve since moved away from mod_wsgi entirely and switched to running Flask apps from containers using the gunicorn WSGI server behind an Apache reverse proxy, which has made life immeasurably easier. In this post we’ll cover running a Flask app on localhost using gunicorn; in Part II we’ll run our app as a service using Singularity and deploy it to production using Apache as a HTTP proxy server.

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