- December 2000 There are 100,000 human gene products and millions of compounds, which make the potential number of experiments to determine beneficial drugs phenomenal. For such large-scale experimental endeavours to be tractable, a technological shift away from present-day laboratory is necessary. New technology in miniaturisation and automation with the aim of uHTS (over 100,000 compounds screened per day) is necessary for the quantum leap in experimental processing power. The potential of these systems will ensure faster and cheaper solutions to discovery, but will it increase the number of marketable blockbuster drugs discovered? This conference explored the rapidly advancing field of HTS, examining the many areas of HTS application. Discussing the dilemmas of identifying viable targets, prioritisation of those targets, development of 'information rich' screens without reducing screening capacity, as well as the essential integration of all these screening, analytical and further parallel synthesis systems in one coherent process. There were also focussed sessions addressing the rapidly advancing areas of ADME tox and formulation screening, as well as the novel area of in silico screening Please find 4 Executive Summaries from papers presented at IBC Life Sciences, HTS Technologies Congress. Please click on one of the below options to view the Executive Summary written from that presentation. In silico Screening and Rational Design in Lead Discovery and Optimisation Detection Methodology: Electrochemiluminescence Chemical Microarray Platform A High Throughput "Hit to Lead" Screening Process for Integrated, Intelligent Discovery for the Future For further information and details of the comprehensive documentation available from this event, please visit: www.ibc-hts.com Details of HTS Technologies 2001, will be available soon, please visit to receive updates: www.ibc-hts.com 1. In silico Screening and Rational Design in Lead Discovery and Optimisation [top] Hugo Kubinyi, Combinatorial Chemistry and Molecular Modelling, ZHF/G - A 30, BASF AG, D-67056 Ludwigshafen, Germany Virtual (in silico) screening increases the chance to find new leads in combinatorial libraries. The very first step in compound or sublibrary selection is the application of garbage filters, to remove e.g. chemically reactive compounds, and of certain diversity filters. Most often the Lipinski (Pfizer) "Rule of Five" is applied as the next step, to eliminate compounds with insufficient bioavailability. Neural net models, developed at BASF, recognise compounds which have a better chance to be biologically active than mere chemicals, either as drugs or as agro compounds. In addition, AIDS antiviral activity, cytotoxicity, and other biological actions can be predicted with the help of such quantitative models. Genetic algorithm procedures select combinatorial sublibraries, out of huge virtual libraries, by a consideration of their activity scores, their chemical diversity, and other desirable properties. Structure-based and computer-aided design techniques are powerful tools for the discovery of new drugs, if the 3D structure of the biological target is known. Success stories include the ACE inhibitor, Captopril, and the HIV protease inhibitors, Saquinavir, Ritonavir, Indinavir, Nelfinavir and Amprenavir. High-affinity ligands of proteins can be rationally designed, using computer programs like: CAVEAT, for the design of rigid analogues, GRID, for the calculation of molecular interaction fields, LUDI, for the de novo design of protein ligands, FlexX, for a flexible docking of ligands into their binding site, and others. The recent development of the potent neuraminidase inhibitor, Zanamivir, as a flu remedy is a success story in computer-assisted drug design. As an outlook into the future, the combinatorial design of ligands in the protein binding site will be illustrated. 2. Detection Methodology: Electrochemiluminescence [top] Dr Jim Wilbur, Director of Research & Development, IGEN, USA IGEN International, Inc. has developed a new detection methodology, electrochemiluminescence, that allows for particularly sensitive and convenient bioanalytical measurements. Electrochemiluminescence uses labels that emit light when stimulated electrochemically. IGEN's technology (trademarked as ORIGEN technology) uses these light-emitting compounds as labels for sensing biological compounds in highly sensitive and precise assays. We have developed products based on electrochemiluminescence in three primary markets: life sciences/drug discovery, clinical (medical) diagnostics and industrial diagnostics. Our products are a mix of instrumentation, reagents and assays. Between these three business units, there are over 6000 systems that use ORIGEN technology on the market today. Electrochemiluminescence and ORIGEN technology represent one of the fundamental detection methods for quantitative analysis of biomolecules. ORIGEN technology offers a broad range of applications, from traditional quantitative assays (binding assays), assays measuring biomolecular interactions (e.g. receptor/ligand, protein/protein, DNA binding) and activity assays (e.g. kinase activity assays, helicase assays). These applications are in use today in drug discovery, from therapeutic areas to high throughput screening to ADME/TOX. Many of our assays are the best in their class. ORIGEN technology offers certain performance benefits that are in high demand, namely highly sensitive assays in a homogeneous format, very rapid assay development times and the ability to conduct complex assays. We are also developing very high throughput formats. This talk will focus on the fundamental science that underlies ORIGEN technology and discuss new assay results and new assay formats that will impact HTS and drug discovery in general. 3. Chemical Microarray Platform [top] Dr. Dirk Vetter, CEO, Graffinity GmbH, Germany The human genome project and related programs have triggered the development of technologies that allow for the efficient identification of disease-related genes. Genomic and proteomic sciences have started to provide huge numbers of new targets for drug screening purposes. However, the future bottleneck is already becoming visible today: the elucidation of the "chemical counterpart" of a target protein (synthetic small organic molecules that are complementary to the gene product´s functional binding sites) is still a tedious, chance-driven process which is essentially too slow and inflexible to manage the challenge of mapping the binding properties of several thousand expected targets. Graffinity envisions to decipher this "chemical code" using chemical microarrays. A chemical microarray is a miniaturized support device with a purposefully designed diversity of immobilized chemical compounds. Key component is the design of a biocompatible surface that presents ligands in a well-defined manner with minimal unspecific background binding. Data will be presented to demonstrate specific biorecognition on a novel surface matrix. The surface chemistry also provides for import of "arrayable" compounds. Such compounds contain the ligand structure as well as a spacer entity for incorporation into the surface matrix. At Graffinity, arrayable chemical compound libraries are preproduced in a parallel, miniaturized format, quality-checked by LC/MS and mapped to the arrays. This process ensures reproducible quality and rapid production. The finished array operates like a preloaded storage element for biological information which is read out when a free target protein as the binding partner is added. Graffinity employs a proprietary label-free array imager for parallel detection of binding events. The device operates on the principle of surface plasmon resonance. Free protein binding to a spot changes the refractive index near the surface and affects the resonance energy of electrons within a metal layer. Reflected visible light carries the information and is read out by an imaging process. The current format of the instrument allows for simultaneous detection of 1536 binding events in a micro titer plate grid. The addition of the biological test sample in a purified form is sufficient to produce the test result. Usually only very little protein material is readily accessible for targets that have freshly come out of genomics or proteomics research. Chemical microarrays are compatible with the restrictions imposed by novel, unvalidated target proteins: lab-scale amounts (submilligram) of protein are sufficient, no radiolabels or fluorescent tags or antibodies are required for protein detection the function of the target does not need to be known an assay does not need to be developed. At the very early post-genomics and post-proteomics stage of the research/drug discovery process chemical microarrays, chemical microarrays provide a seamless set of tools and information to very rapidly derive chemical binding patterns and ultimately drug-like molecules. Chemical microarrays will address relevant questions such as: does the target protein show any propensity to bind to small molecules? if it does, is this binding related to already known structures? if not, what is the class of compounds that would have to be screened? which library will have to be designed? are there more than one binding site on the target protein? do compounds interact to give additive or multiplicative binding effects? do compounds bind at the active center or elsewhere? do compounds induce an allosteric effect? can one apply novel analoging strategies starting from identified substructures? Data will be presented, that demonstrate the detection of small organic molecule compound library screening in a chemical microarray format with label-free detection for a representative drug target protein. 4. A High Throughput "Hit to Lead" Screening Process for Integrated, Intelligent Discovery for the Future [top] Stuart Swinburne, Ph.D., Senior Project Manager, Research & Development, Amersham Pharmacia Biotech (AP Biotech), Cardiff, U.K. The major challenge of high throughput (HT) ADME-Tox. studies is to get the quality of data larger studies provide, in a HT testing context. This requires balancing the opposing needs for complex physiological test systems for greater predictivity, with "simple" systems for enabling HT. AP Biotech is developing Intelligent Test Portfolios to enhance predictivity. This principle was initially demonstrated using a selected panel of riboprobes to key target genes involved in DNA damage and repair. This panel was used on target cells treated with sub-cytotoxic doses of test compounds in the Cytostar scintillating microplate HT test format. The two day HT test protocol was 85% predictive of DNA damage properties of compounds. Currently, this concept is being extended to include multiple cell functions. Intelligent "genetic programming" is being used to identify portfolios of our tests that give the best prediction of toxicity. Intelligent test portfolios require dedicated HT technology platforms. AP Biotech is currently applying its LEADseeker imaging technology to this, starting with assays to measure cytochrome P450s. A further development of the LEADseeker platform is allowing us to look at intra-cellular targets in individual cells in HT, with real time data capture and analysis. Future developments will facilitate evolution of target measurement to cell function development. In strategic alliance with leading informatics and software companies, AP Biotech is working with pharmaceutical companies to develop integrated HT screening systems to effectively transform "hits to leads".