SLIDE 91 Beyond molecular fingerprints: conv nets on graphs
Convolutional Networks on Graphs for Learning Molecular Fingerprints
David Duvenaud†, Dougal Maclaurin†, Jorge Aguilera-Iparraguirre Rafael G´
- mez-Bombarelli, Timothy Hirzel, Al´
an Aspuru-Guzik, Ryan P. Adams Harvard University
Abstract
We introduce a convolutional neural network that operates directly on graphs. These networks allow end-to-end learning of prediction pipelines whose inputs are graphs of arbitrary size and shape. The architecture we present generalizes standard molecular feature extraction methods based on circular fingerprints. We show that these data-driven features are more interpretable, and have better pre- dictive performance on a variety of tasks.
These neural graph fingerprints offer several advantages over fixed fingerprints:
- Predictive performance. By using data adapting to the task at hand, machine-optimized
fingerprints can provide substantially better predictive performance than fixed fingerprints. We show that neural graph fingerprints match or beat the predictive performance of stan- dard fingerprints on solubility, drug efficacy, and organic photovoltaic efficiency datasets.
- Parsimony. Fixed fingerprints must be extremely large to encode all possible substructures
without overlap. For example, [28] used a fingerprint vector of size 43,000, after having removed rarely-occurring features. Differentiable fingerprints can be optimized to encode
- nly relevant features, reducing downstream computation and regularization requirements.
- Interpretability. Standard fingerprints encode each possible fragment completely dis-
tinctly, with no notion of similarity between fragments. In contrast, each feature of a neural graph fingerprint can be activated by similar but distinct molecular fragments, making the feature representation more meaningful.
Molecular Graph Convolutions: Moving Beyond Fingerprints
Steven Kearnes Stanford University kearnes@stanford.edu Kevin McCloskey Google Inc. mccloskey@google.com Marc Berndl Google Inc. marcberndl@google.com Vijay Pande Stanford University pande@stanford.edu Patrick Riley Google Inc. pfr@google.com
Abstract Molecular “fingerprints” encoding structural information are the workhorse of cheminfor- matics and machine learning in drug discovery
- applications. However, fingerprint representa-
tions necessarily emphasize particular aspects
- f the molecular structure while ignoring others,
rather than allowing the model to make data- driven decisions. We describe molecular graph convolutions, a machine learning architecture for learning from undirected graphs, specifically small molecules. Graph convolutions use a sim- ple encoding of the molecular graph—atoms, bonds, distances, etc.—which allows the model to take greater advantage of information in the graph structure. Although graph convolutions do not outperform all fingerprint-based meth-
- ds, they (along with other graph-based meth-
- ds) represent a new paradigm in ligand-based
virtual screening with exciting opportunities for future improvement.
1 Introduction
Computer-aided drug design requires representations
- f molecules that can be related to biological activ-
ity or other experimental endpoints. These repre- sentations encode structural features, physical prop- erties, or activity in other assays [Todeschini and Consonni, 2009; Petrone et al., 2012]. The recent advent of “deep learning” has enabled the use of very raw representations that are less application- specific when building machine learning models [Le- Cun et al., 2015]. For instance, image recognition models that were once based on complex features ex- tracted from images are now trained exclusively on the pixels themselves—deep architectures can “learn” appropriate representations for input data. Conse- quently, deep learning systems for drug screening or
Figure 1: Molecular graph for ibuprofen. Unmarked ver- tices represent carbon atoms, and bond order is indicated by the number of lines used for each edge.
design should benefit from molecular representations that are as complete and general as possible rather than relying on application-specific features or encod- ings. First-year chemistry students quickly become fa- miliar with a common representation for small molecules: the molecular graph. Figure 1 gives an example of the molecular graph for ibuprofen, an over-the-counter non-steroidal anti-inflammatory
- drug. The atoms and bonds between atoms form the
nodes and edges, respectively, of the graph. Both atoms and bonds have associated properties, such as atom type and bond order. Although the basic molec- ular graph representation does not capture the quan- tum mechanical structure of molecules or necessarily express all of the information that it might suggest to an expert medicinal chemist, its ubiquity in academia and industry makes it a desirable starting point for machine learning on chemical information. Here we describe molecular graph convolutions, a deep learning system using a representation of small molecules as undirected graphs of atoms. Graph con- 1
(Kearnes, McCloskey, Berndl, VSP, Riley)