Drug Targets their role in drug design / discovery

1. Drug Targetstheir role in drug design / discovery l2PHA406 - Drug Design

2. At the end of the 20th C the set of drug targets for the pharmaceutical industry was ~ 500, 45% cell membrane receptors (including GPCR) 28% enzymes 11% hormone 5% ion channels 2% nuclear receptors 2% DNA 7% Unknown targets Drug targets - complement of targets, end of the 20thC l2PHA406 - Drug Design

3. Human genome statistics Size 3.2 G bases Repeated sequences 53% of genome Transcribed into RNA 28% of genome Protein encoded genes 1.1 - 1.4 % of genome Vertebrate specific 7% of all genes Drug targets - Human genome statistics l2PHA406 - Drug Design

4. Of the ~ 30,000 human genes only a minority might be interesting targets, estimates range from 3,000 - 10,000. Many proteins have an orphan status, structure known, function or natural ligand unknown. Compared to the current state of play at the end of the 20th C that is at least an order of magnitude increase in number of targets. Novel techniques have been developed to rapidly validate targets by elucidating their role in physiological processes (Molecular Biology and Pharmacology). Functional Genomics or Chemical Genomics are some other approaches (Chemical, Bioinformatics) to elucidate structure / function relationships. Drug targets - complement of targets, post HGP l2PHA406 - Drug Design

5. DNA RNA Protein Human AGGCGGAATAGC -Y-G-A-L-P- Mouse AGGCGAAATAGC -Y-G-A-V-P- Drug targets - reminder HG and other organisms E.coli AGCCGAAATAGC -Y-D-A-L-P- Eukaryotic genomes (Mouse, Human, C.elegans) Prokaryotic genomes (E.coli, Helicobacter pylori) Comparative proteomics Comparative genomics l2PHA406 - Drug Design

6. Predicted number of potential drug targets belonging to different chemical classes (rough estimation, Jan 2001) Drug targets - breakdown of target types post HGP Ion Channels (1000) Enzymes (3500) Nuclear Hormone Receptors (>150) GPCR (2000) Total targets (6650) l2PHA406 - Drug Design

7. Mn+ Ion Channels (Over-expressed channels in screening cell lines, internalised fluorescent ion probes) L Enzymes (Surrogate substrates that release fluorescent products) X [ IP.Mn+] S P+P* Nuclear Hormone Receptors (Ligands binding to NHR responsive genes controlling expression of reporter genes) L L* Fluorescent outcome GPCR (Over-expressed channels in screening cell lines or membrane preparations, assess ligand binding by fluorescence techniques ) Transcription of reporter product Drug targets - types and high throughput screening (HTS) l2PHA406 - Drug Design

8. Ion Channels Enzymes Drug targets - HTS of compound libraries against targets for lead discovery Compound sub-library Nuclear Hormone Receptors GPCR l2PHA406 - Drug Design

9. Ion Channels (Membrane bound) Enzymes (Mixed membrane bound and soluble) Drug targets - properties Nuclear Hormone Receptors (Soluble proteins) GPCR (Membrane bound) l2PHA406 - Drug Design

10. Drug targets - target structures Membrane bound systems are difficult to get 3D information on for designing drugs against, as the proteins are exceedingly difficult to crystallise. Computer models may be constructed by homology modelling with related systems that have crystallised. Soluble proteins, and their complexes, are highly desirable due to the relative ease by which crystals may be obtained. This process can be carried out by automated high throughput techniques. In both instances NMR is making a contribution to elucidating structure, with more success with soluble proteins l2PHA406 - Drug Design

11. Purification DNA Cloning Expression Data Collection Cryo-preservation Crystallisation Data Analysis Final Model Drug targets - pure proteins for crystal structure determination l2PHA406 - Drug Design

12. Protein active site Crystallised complex Protein active site model Real / Virtual library Crystal structure of target protein Lead compound Drug targets - why structural knowledge of targets? l2PHA406 - Drug Design

13. Definition Proteomics includes not only the identification and quantification of proteins, but also the determination of their localisation, modifications, interactions, activities, and, ultimately, their function." To this definition, maybe added structural genomics, the rapid 3-D structure determination of large numbers of proteins (on a proteome scale). Drug targets - proteomics l2PHA406 - Drug Design

14. * ALLIED TECHNIQUES EMPLOYED FOR IDENTIFICATION AND/OR STRUCTURAL ELUCIDATION OF PROTEINS INCLUDE HIGH RESOLUTION MASS SPECTROMETRY HIGH RESOLUTION N.M.R. SPECTROSCOPY * Drug targets - proteomics in identifying valid targets * l2PHA406 - Drug Design

15. Drug targets - development, avoiding side effects l2PHA406 - Drug Design

16. Bioinformatics - definition The creation and development of advanced information and computational technologies for problems in biology, most commonly molecular biology (but increasingly in other areas of biology). As such, it deals with methods for storing, retrieving and analysing biological data, such as nucleic acid (DNA/RNA) and protein sequences, structures, functions, pathways and genetic interactions. Drug targets - bioinformatics l2PHA406 - Drug Design

17. Bioinformatics main role in the drug design process is primarily through ready access to genomic, transcriptomic, proteomic, metabolomic (metabonomic) data. Drug targets - nature of bioinformatics Genome DNA sequence (protein coding) and function (control) Transcriptome RNA structure and function (transcription) Proteome 1,2,3D sequence and 4D (temporal) data (translation) Metabolome metabolic data (ultimate goal is to elucidate the metabolic pathways on a cell type basis) all of these may be appended by the word Comparative (organism variation). All of these areas of “omics” have WWW accessible databases. l2PHA406 - Drug Design