improved predictions in structure-based drug design using cart and bayesian models

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Donovan N. Chin & R. Aldrin Denny

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Page 1: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

Donovan N. Chin & R. Aldrin Denny

Page 2: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

Traditional Drug Discovery (insert graph)

In Silico Prediction of ADME (insert graph)◦ Potency

◦ Absorption

◦ Lead

◦ Drug

◦ Toxicity

◦ Excretion

◦ Metabolism

◦ distribution

Page 3: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

Target IVY(Brute force virtual screening of very large compound libraries) Lead Discovery IVY(Utilize predictive models from Biogen data for more efficient virtual screening) Lead Optimization candidate

Page 4: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

(insert graph)◦ Potency

◦ Lead

◦ Drug

◦ Toxicity

◦ Excretion

◦ Metabolism

◦ Distribution

◦ absorption

Page 5: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

Goal: Identify crystallographic binding mode, Rank order ligands wrt binding with protein

(insert graph)

Receptor Docking

Ligand Shape

Generate plausible trial binding modes using docking function then Re-rank modes with scoring function

Page 6: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

(insert graph)

341 Active

47 Non-Active

Page 7: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

(insert graph)

After filtering by Pharmacophore Feature

Page 8: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

(insert graph)

Page 9: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

(insert functions for)◦ F_Score*

◦ D_Score

◦ G_Score

◦ PMF_Score

◦ Chem_Score

◦ ICM_Score*

Page 10: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

Cell Adhesion Assay (50% Serum)◦ (insert graph)

Biochemical Adhesion Assay◦ (insert graph)

Scoring Functions Are Poor More Often Than Not

Page 11: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

Receptor Site View Library Design FlexXScore Consensus Score>=3 e.g. Contact Map, CLogP MW, HBOND Rotatable bondsConsensus=5? if yes, substructure exists?if yes, Pharmacophore<4.2Å? if yes, Publish Hit Report

Page 12: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

(insert graph)

Page 13: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

Goal: Predict hit/miss class based on presence of features (fingerprints)

Method◦ Given a set of N samples◦ Given that some subset A of them are good („active‟) Then we estimate for a new compound: P(good)~ A/N

◦ Given a set of binary features F For a given feature F:

It appears in N samples

It appears in A good samples

Can we estimate: P(good l F)~A/N (Problem: Error gets worse as Nsmall)

◦ P‟(good l F)= (A+P(good)k)/(n+k) P‟(good l F)p(good)as N0 P‟(good l F) A/N as N large

◦ (If K=1/P(good) this is the Laplacian correction)

Descriptors (insert) Advantages

◦ Can describe huge number of features (up to 4 billion; MDL 1024; Lead scope 27,000)

◦ Contains tertiary and stereochemistry information◦ Fast

Page 14: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

Classification Analysis

◦ Developing Non-Linear Scoring Functions to classify actives and non-actives

◦ (insert graphs)

◦ Cost Function to Minimize: Gini Impurity N= 1-ΣP^2(ω)

Page 15: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

Training Set Prediction Success

(insert table)

10-fold cross validation

Randomly split training and test sets

Significant Improvement in Separating Actives from Non-Actives

Page 16: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

(insert graph)

Significant Improvement in Finding Hits Using New SF

Page 17: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

Optimal tree identified (insert graph)

No random effects (insert graph)

Page 18: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

(insert cluster)

Able to identify different molecular property criteria that lead to hits

Page 19: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

(insert graph)

Page 20: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

(insert graph)

Size= magnitude of OBA

OBA values cover range of descriptor space

Page 21: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

(insert graph)

Choose 1 & 2D Descriptors for ease of interpretation and lower “noise”

Page 22: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

Build Model (insert graphs) Apply Model

Page 23: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

Features found in high OBA

Features found in low OBA

Would be nice if CART did similar view

Page 24: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

Improved scoring functions for separating hits from non-hits in structure-based drug design developed with CART and Bayesian models

Identified key differences in molecular physical properties that led to hits

Built reasonably predictive OBA model (cannot expect method to extend to other systems given complexity of OBA, however)

Page 25: Improved Predictions in Structure-Based Drug Design Using CART and Bayesian Models

Biogen IDEC

Modeling ◦ Rajiah Denny◦ Claudio Chuaqui◦ Juswinder Singh◦ Herman van Vlijmen◦ Norman Wang◦ Anuj Patel◦ Zhan Deng

Chemistry◦ Kevin Guckian◦ Dan Scott◦ Thomas Durand-Reville◦ Pat Conlon◦ Charlie Hammond◦ Chuck Jewell

Pharmacology◦ Tonika Bonhert