Machine Learning

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Computer-aided Vaccine and Drug Discovery

G.P.S. Raghava

 Understanding immune system

 Breaking complex problem

 Adaptive immunity

 Innate Immunity

 Vaccine delivery system

 ADMET of peptides

 Annotation of genomes

 Searching drug targets

 Properties of drug molecules

 Protein-chemical interaction

 Prediction of drug-like molecules

1

Adaptive Immunity

Innate Immunity

WHOLE

ORGANISM

Bioinformatics Centre

IMTECH, Chandigarh

Purified Antigen

Protective Antigens

Vaccine Delivery

Epitopes (Subunit

Vaccine)

T cell epitope

Attenuated

Limitations of methods of subunit vaccine design

– Methods for one or two MHC alleles

Do not consider pathways of antigen processing

– Limited to T-cell epitopes

Initiatives taken by our group

Understand complete mechanism of antigen processing

– Develop better and comprehensive methods

– Promiscuous MHC binders 2

Adaptive Immunity

Innate Immunity

Disease Causing

Agents

Bioinformatics Centre

IMTECH, Chandigarh

Protective Antigens

Vaccine Delivery

3

Pathogens/Invaders

Adaptive Immunity

Innate Immunity

Protective Antigens

Vaccine Delivery

ER

TAP

Prediction of CTL Epitopes (Cell-mediated immunity)

4

Adaptive Immunity

Innate Immunity

Protective Antigens

Vaccine Delivery

5

Adaptive Immunity

Innate Immunity

MHCBN: A database of MHC/TAP binders and T-cell epitopes

Distributed by EBI, UK

Reference database in T-cell epitopes

Highly Cited ( ~ 70 citations)

Bhasin et al. (2003) Bioinformatics 19: 665

Bhasin et al. (2004) NAR (Online)

Protective Antigens

Vaccine Delivery

6

Adaptive Immunity

Innate Immunity

Protective Antigens

Vaccine Delivery

Prediction of MHC II Epitopes ( T helper

Epitopes)

Propred: Promiscuous of binders for 51 MHC Class II binders

Virtual matrices

– Singh and Raghava (2001) Bioinformatics 17:1236

HLADR4pred : Prediction of HLA-DRB1*0401 binding peptides

Dominating MHC class II allele

ANN and SVM techniques

– Bhasin and Raghava (2004) Bioinformatics 12:421.

MHC2Pred: Prediction of MHC class II binders for 41 alleles

Human and mouse

– Support vector machine (SVM) technique

– Extension of HLADR4pred

MMBpred : Prediction pf Mutated MHC Binder

– Mutations required to increase affinity

– Mutation required for make a binder promiscuous

Bhasin and Raghava (2003) Hybrid Hybridomics, 22:229

MOT : Matrix optimization technique for binding core

MHCBench: Benchmarting of methods for MHC binders

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Adaptive Immunity

Innate Immunity

Protective Antigens

Vaccine Delivery

Prediction of MHC I binders and CTL Epitopes

Propred1 : Promiscuous binders for 47 MHC class I alleles

– Cleavage site at C-terminal

Singh and Raghava (2003) Bioinformatics 19:1109 nHLApred: Promiscuous binders for 67 alleles using ANN and QM

– Bhasin and Raghava (2007) J. Biosci. 32:31-42

TAPpred: Analysis and prediction of TAP binders

– Bhasin and Raghava (2004) Protein Science 13:596

Pcleavage : Proteasome and Immuno-proteasome cleavage site.

– Trained and test on in vitro and in vivo data

Bhasin and Raghava (2005) Nucleic Acids Research 33: W202-7

CTLpred: Direct method for Predicting CTL Epitopes

Bhasin and Raghava (2004) Vaccine 22:3195 8

Adaptive Immunity

Innate Immunity

Protective Antigens

Vaccine Delivery

9

Adaptive Immunity

Innate Immunity

BCIPEP: A database of

B-cell epitopes.

Saha et al.(2005) BMC Genomics 6:79.

Saha et al. (2006) NAR (Online)

Protective Antigens

Vaccine Delivery

10

Adaptive Immunity

Innate Immunity

Protective Antigens

Vaccine Delivery

Prediction of B-Cell Epitopes

• BCEpred: Prediction of Continuous B-cell epitopes

Benchmarking of existing methods

Evaluation of Physico-chemical properties

– Poor performance slightly better than random

– Combine all properties and achieve accuracy around 58%

– Saha and Raghava (2004) ICARIS 197-204.

• ABCpred: ANN based method for B-cell epitope prediction

– Extract all epitopes from BCIPEP (around 2400)

700 non-redundant epitopes used for testing and training

– Recurrent neural network

– Accuracy 66% achieved

Saha and Raghava (2006) Proteins,65:40-48

• ALGpred: Mapping and Prediction of Allergenic Epitopes

– Allergenic proteins

IgE epitope and mapping

– Saha and Raghava (2006) Nucleic Acids Research 34:W202-W209 11

Adaptive Immunity

Innate Immunity

Protective Antigens

Vaccine Delivery

HaptenDB: A database of hapten molecules

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13

Adaptive Immunity

Innate Immunity

Bioinformatics Centre

IMTECH, Chandigarh

PRRDB is a database of pattern recognition receptors and their ligands

~500 Pattern-recognition Receptors

228 ligands (PAMPs)

77 distinct organisms

720 entries

Protective Antigens

Vaccine Delivery

14

Adaptive Immunity

Innate Immunity

Bioinformatics Centre

IMTECH, Chandigarh

Protective Antigens

Vaccine Delivery

15

Adaptive Immunity

Innate Immunity

Bioinformatics Centre

IMTECH, Chandigarh

Major Challenges in Vaccine Design

ADMET of peptides and proteins

Activate innate and adaptive immunity

Prediction of carrier molecules

Avoid cross reactivity (autoimmunity)

Prediction of allergic epitopes

Solubility and degradability

Absorption and distribution

Glycocylated epitopes

Protective Antigens

Vaccine Delivery

16

Searching and analyzing druggable targets

Nucleotide

Genome

Annotation

Proteome

Annotation

Protein

Protein

Struct.

Target

Proteins

Drug

Informatics

Prediction and analysis of drug molecules

Biologicals

Protein

Chemical s

Protein-drug

Drugs

Interaction

Drug-like

Molecules

17

Searching and analyzing druggable targets

Nucleotide

Genome

Annotation

Proteome

Annotation

Protein

Protein

Struct.

Target

Proteins

Drug

Informatics

Prediction and analysis of drug molecules

Biologicals

Protein

Chemical s

Protein-drug

Drugs

Interaction

Drug-like

Molecules

FTGpred: Prediction of Prokaryotic genes

– Ab initio method for gene prediction using FFT technique

– Issac et al. (2002) Bioinformatics 18:197

EGpred: Prediction of eukaryotic genes

– BLASTX against RefSeq & BLASTN against intron database

– NNSPLICE program is used to reassign splicing signal site positions

– Issac and Raghava (2004) Genome Research 14:1756

GeneBench: Benchmarking of gene finders

– Collection of different datasets

– Tools for evaluating a method

– Creation of own datasets

SRF: Spectral Repeat finder

– FFT based repeat finder

– Sharma et al. (2004) Bioinformatics 20: 1405

Work in Progress

Prediction of polyadenylation signal (PAS) in human coding DNA

Understanding DICER cutter sites and siRNA/miRNA efficacy

Predict transcription factor binding sites in DNA sequences

18

Searching and analyzing druggable targets

Nucleotide

Genome

Annotation

Proteome

Annotation

Protein

Protein

Struct.

Target

Proteins

Comparative genomics

GWFASTA: Genome Wide FASTA

Search

– Analysis of FASTA search for comparative genomics

– Biotechniques 2002, 33:548

Drug

Informatics

GWBLAST: Genome wide BLAST search

COPID: Composition based similarity search

LGEpred: Expression of a gene from its Amino acid sequence

– BMC Bioinformatics 2005, 6:59

ECGpred: Expression from its nucleotide sequence

Prediction and analysis of drug molecules

Biologicals

Protein

Chemical s

Protein-drug

Drugs

Interaction

Drug-like

Molecules

19

Searching and analyzing druggable targets

Nucleotide Protein

Genome

Annotation

Proteome

Annotation

Protein

Struct.

Target

Proteins

Drug

Informatics

Prediction and analysis of drug molecules

Biologicals

Protein

Chemical s

Protein-drug

Drugs

Interaction

Drug-like

Molecules

Subcellular localization Methods

PSLpred: Subcellular localization of prokaryotic proteins

– 5 major sub cellular localization

– Bioinformatics 2005, 21: 2522

ESLpred: Subcellular localization of Eukaryotic proteins

– SVM based method

– Amino acid, Dipetide and properties composition

– Sequence profile (PSIBLAST)

– Nucleic Acids Research 2004, 32:W414-9

HSLpred : Sub cellular localization of Human proteins

– Need to develop organism specific methods

84% accuracy for human proteins

Journal of Biological Chemistry 2005, 280:14427-32

MITpred: Prediction of Mitochndrial proteins

Exclusive mitochndrial domain and SVM

J Biol Chem. 2005, 281:5357-63.

Work in Progress: Subcellular localization of M.Tb. and malaria

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Searching and analyzing druggable targets

Nucleotide

Genome

Annotation

Proteome

Annotation

Protein

Protein

Struct.

Target

Proteins

Drug

Informatics

Prediction and analysis of drug molecules

Biologicals

Protein

Chemical s

Protein-drug

Drugs

Interaction

Drug-like

Molecules

Regular Secondary Structure Prediction (

-helix

-sheet)

• APSSP2: Highly accurate method for secondary structure prediction

Competete in EVA, CAFASP and CASP (In top 5 methods)

Irregular secondary structure prediction methods (Tight turns)

• Betatpred : Consensus method for

-turns prediction

– Statistical methods combined

– Kaur and Raghava (2001) Bioinformatics

• Bteval : Benchmarking of

-turns prediction

– Kaur and Raghava (2002) J. Bioinformatics and Computational Biology, 1:495:504

• BetaTpred2 : Highly accurate method for predicting

-turns (ANN, SS, MA)

– Multiple alignment and secondary structure information

– Kaur and Raghava (2003) Protein Sci 12:627-34

• BetaTurns : Prediction of

-turn types in proteins

– Kaur and Raghava (2004) Bioinformatics 20:2751-8.

• AlphaPred : Prediction of

-turns in proteins

– Kaur and Raghava (2004) Proteins: Structure, Function, and Genetics 55:83-90

GammaPred : Prediction of

-turns in proteins

– Kaur and Raghava (2004) Protein Science; 12:923-929 .

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Searching and analyzing druggable targets

Nucleotide

Genome

Annotation

Proteome

Annotation

Protein

Protein

Struct.

Target

Proteins

Drug

Informatics

Prediction and analysis of drug molecules

Biologicals

Protein

Chemical s

Protein-drug

Drugs

Interaction

Drug-like

Molecules

Supersecondary Structure

BhairPred : Prediction of Beta Hairpins

– Secondary structure and surface accessibility used as input

– Manish et al. (2005) Nucleic Acids Research 33:W154-9

TBBpred: Prediction of outer membrane proteins

– Prediction of trans membrane beta barrel proteins

– Application of ANN and SVM + Evolutionary information

– Natt et al. (2004) Proteins: 56:11-8

ARNHpred: Analysis and prediction side chain, backbone interactions

– Prediction of aromatic NH interactions

– Kaur and Raghava (2004) FEBS Letters 564:47-57 .

Chpredict : Prediction of C-H .. O and PI interaction

– Kaur and Raghava (2006) In-Silico Biology 6:0011

SARpred : Prediction of surface accessibility (real accessibility)

– Multiple alignment (PSIBLAST) and Secondary structure information

– Garg et al., (2005) Proteins 61:318-24

Secondary to Tertiary Structure

PepStr : Prediction of tertiary structure of Bioactive peptides

– Kaur et al. (2007) Protein Pept Lett. (In Press)

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Searching and analyzing druggable targets

Nucleotide Protein

Genome

Annotation

Proteome

Annotation

Protein

Struct.

Target

Proteins

Drug

Informatics

Prediction and analysis of drug molecules

Biologicals

Protein

Chemical s

Protein-drug

Drugs

Interaction

Drug-like

Molecules

23

Searching and analyzing druggable targets

Nucleotide Protein

Genome

Annotation

Proteome

Annotation

Protein

Struct.

Target

Proteins

Drug

Informatics

Prediction and analysis of drug molecules

Biologicals

Protein

Chemical s

Protein-drug

Drugs

Interaction

Drug-like

Molecules

Nrpred : Classification of nuclear receptors

BLAST fails in classification of NR proteins

– Uses composition of amino acids

Journal of Biological Chemistry 2004, 279: 23262

GPCRpred : Prediction of G-protein-coupled receptors

– Predict GPCR proteins & class

– > 80% in Class A, further classify

Nucleic Acids Research 2004, 32:W383

GPCRsclass : Amine type of GPCR

Major drug targets, 4 classes,

– Accuracy 96.4%

Nucleic Acids Research 2005, 33:W172

VGIchan: Voltage gated ion channel

– Genomics Proteomics & Bioinformatics 2007, 4:253-8

Pprint: RNA interacting residues in proteins

– Proteins: Structure, Function and Bioinformatics (In Press)

GSTpred: Glutathione S-transferases proteins

Protein Pept Lett. 2007, 6:575-80

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Searching and analyzing druggable targets

Nucleotide

Genome

Annotation

Proteome

Annotation

Protein

Protein

Struct.

Target

Proteins

Drug

Informatics

Prediction and analysis of drug molecules

Biologicals

Protein

Chemical s

Protein-drug

Drugs

Interaction

Drug-like

Molecules

Antibp: Analysis and prediction of antibacterial peptides

• Searching and mapping of antibacterial peptide

BMC Bioinformatics 2007, 8:263

ALGpred: Prediction of allergens

•Using allergen representative peptides

Nucleic Acids Research 2006, 34:W202-9.

BTXpred: Prediction of bacterial toxins

•Classifcation of toxins into exotoxins and endotoxins

•Classification of exotoxins in seven classes

In Silico Biology 2007, 7: 0028

• NTXpred: Prediction of neurotoxins

Classification based on source

Classification based on function (ion channel blockers, blocks

Acetylcholine receptors etc.)

• In Silico Biology 2007, 7, 0025

25

Searching and analyzing druggable targets

Nucleotide

Genome

Annotation

Proteome

Annotation

Protein

Protein

Struct.

Target

Proteins

Drug

Informatics

Prediction and analysis of drug molecules

Biologicals

Protein

Chemical s

Protein-drug

Drugs

Interaction

Drug-like

Molecules

Work in Progress (Future Plan)

1. Prediction of solubility of proteins and peptides

2. Understand drug delivery system for protein

3. Degradation of proteins

4. Improving thermal stability of a protein ( Protein

Science 12:2118-2120 )

5. Analysis and prediction of druggable proteins/peptide

26

Searching and analyzing druggable targets

Nucleotide

Genome

Annotation

Proteome

Annotation

Protein

Protein

Struct.

Target

Proteins

Drug

Informatics

Prediction and analysis of drug molecules

Biologicals

Protein

Chemical s

Protein-drug

Drugs

Interaction

Drug-like

Molecules

MELTpred: Prediction of melting point of chemical compunds

Around 4300 compounds were analzed to derive rules

Successful predicted melting point of 277 drug-like molecules

Future Plan

1. QSAR models for ADMET

2. QSAR + docking for ADMET

3. Prediction of drug like molecules

4. Open access in Chemoinformatics

27

Searching and analyzing druggable targets

Nucleotide Protein

Genome

Annotation

Proteome

Annotation

Protein

Struct.

Target

Proteins

Drug

Informatics

Prediction and analysis of drug molecules

Biologicals

Protein

Chemical s

Protein-drug

Drugs

Interaction

Drug-like

Molecules

Understanding Protein-Chemical Interaction

Prediction of Kinases Targets and Off Targets

Kinases inhibitors were analyzed

• Model build to predict inhbitor against kinases

Cross-Specificity were checked

Useful for predicting targets and off targets

Future Plan

• Classification of proteins based on chemical interaction

Clustering drug molecules based on interaction with proteins

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