Glossary A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Absorption Process of taking in; chemicals can be absorbed into the bloodstream after breathing or swallowing. ADMET Investigation of Absorption Distribution Metabolism Excretion and Toxicology. Adverse effect Undesirable and unintended, although not necessarily unexpected, result of therapy or other treatment. Agonist Drug that binds cellular receptors which are ordinarily stimulated by naturally occurring substances, triggering a response. Amino acid Any of a class of 20 molecules that are combined to form proteins in living organisms. Amino acid sequence Linear order of the amino acids in a protein or peptide. Amplification "Increase in the number of copies of a specific DNA fragment; can be in vivo or in vitro. See cloning, polymerase chain reaction." Antagonist Compound that binds a receptor without triggering a response. Antibiotics Drugs that fight infection by killing bacteria and other micro-organisms. Antibody Protein produced by certain white blood cells in response to a foreign substance (antigen). Each antibody can bind only to a specific antigen. Antigen Any foreign or ’non-self’ substance that causes the immune system to create an antibody. Anti-infective Drug used to treat infections caused by bacteria, protozoa, and other micro-organisms. Assay Any combination of targets and compounds which is exposed to a detection device to measure chemical or biological activity. Beads Small spheres (a few micrometers in diameter) made of polysterene or other polymers used as solid carrier material for chemical synthesis of compounds Biochemical assay Assay run on targets without cells. Cell Smallest membrane-bound biological unit capable of replication. Cell membrane The phospholipid bilayer that surrounds a cell, forming a selectively permeable barrier. Cellular assay Assay run on whole living cells. Chromatography Separation of a mixture by flowing it through or around stationary materials which selectively delay or adsorb components of the mixture. Chromosome "Single DNA molecule; the DNA-bearing structure that carries the inheritable characteristics of an organism." Clinical trials Research studies that involve humans. Clone Group of identical genes, cells, or organisms derived from a single ancestor. Cloned DNA Any DNA fragment that passively replicates in the host organism after it has been joined to a cloning vector. Cloning Process of making genetically identical copies. Cloning vector Molecular vehicle for introducing and replicating recombinant DNA in host organisms. Combinatorial chemistry Chemical synthesis that creates large numbers of organic compounds by putting chemical 'building blocks' together in every possible combination. CoMFA Comparative molecular field analysis; a 3D QSAR method developed by Tripos which uses PLS statistics and electrostatic/steric fields. Compound Substance made up of two or more elements that cannot be separated. Diffusion Molecular movement from areas of high concentration to areas of low concentration. Deoxyribonucleic acid (DNA) carrier of genetic information and blueprint of proteins. DNA See Deoxyribonucleic acid Docking Computer simulation of the binding interaction of a small molecule compound with a protein structure. Drug Any chemical compound that may be used on humans to help in diagnosis, treatment, cure, mitigation, or prevention of disease or other abnormal conditions. E. coli Common non-pathogenic bacterium; easy to grow in the laboratory, often used as host cells. Enzyme Protein that acts as a catalyst, affecting the rate at which chemical reactions occur in cells. False negative When a test wrongly shows an effect or condition to be absent. False positive When a test wrongly shows an effect or condition to be present. Femto Amount of 1x10-15 Fermenter Bioreactor used to manufacture or modify products (compounds) with help of micro-organisms. Fluorescence Process whereby colours (dyes) absorb radiant power at one wavelength and immediately re-emit it at another (usually longer) wavelength. Fluorescence lifetime Average time that a population of fluorophores spends in the excited state before collapse to the ground state. Fluorescence polarization Measure of the mobility of a fluorophore: A mobile fluorophore is able to reorient itself within its fluorescence lifetime and therefore emits unpolarized light; an immobile fluorophore does not reorient and hence emits light polarized in the plane of exc. Fluorophore Optically active part of a fluorescent dye molecule. Gene "Unit of inheritance; a working subunit of DNA containing the code for a specific product, typically, a protein such as an enzyme." Gene expression Process by which a gene’s coded information is translated into the structures present and operating in the cell (either proteins or RNAs). Gene markers Landmarks for a target gene, either detectable traits that are inherited along with the gene, or distinctive segments of DNA. Gene product Biochemical material, either RNA or protein, resulting from expression of a gene. Generic assay Assay formulations of identical composition with respect to the target. Genetics Scientific study of heredity how particular qualities or traits are transmitted from parents to offspring. Genome All the genetic material in the chromosomes of a particular organism; its size is generally given as its total number of base pairs. Genome projects Research and technology development efforts aimed at mapping and sequencing some or all of the genome of human beings and other organisms. Genomics Identification and functional characterization of genes. Genotype Genetic constitution of an organism. High Performance Liquid Chromatography (HPLC) Chromatography method with very high degree of resolution using high pressures to force the mixture to be separated to pass through a column containing the separating resin. High Throughput Screening (HTS) Technique of rapidly searching for molecules with desired biological effects from very large compound libraries. Hit Compound found by screening to have a significant biological effect e.g. IC50 < 10 µM. Homogeneous assay Assay which does not require any chemical modification or purification steps after the reaction has started. HPLC See High Performance Liquid Chromatography HTS See High Throughput Screening Human Genome Project International research effort aimed at mapping and sequencing all of the genome of the human species. Hybridization Process of joining two complementary strands of DNA or one each of DNA and RNA to form a double-stranded molecule. In vitro In a test tube. In vivo In the living organism as opposed to in vitro. IND Investigational new drug; application must be approved by the Food and Drug Administration (FDA) before a drug can be tested in humans in clinical trials. Ion channel Protein which allows the passage of ions across cell membranes. Lead Substance that is chosen for experimental evaluation on the basis of its predicted qualities and its likelihood of leading to a drug discovery. Library Collection of a multitude of different molecules for screening. Ligand Chemical compound, usually released by one cell to communicate with a different cell by binding to specific receptors on the receiving cell’s surface. Liquid handling Pipetting, pumping and dispensing of volumes of liquid. Metabolism All the chemical reactions in an organism that enable the organism to live. Messenger RNA (mRNA) RNA that serves as a template for protein synthesis. Molar 1 mole of a compound per liter solvent. ’Mole’ is used in chemistry to express a number of molecules (6,623x1023). mRNA See Messenger RNA Micro Amount of 1 x 10-6 Micro-organisms Single-cell organisms, for example bacteria and fungi, but not viruses. Nano Amount of 1 x 10-9 Nanomolar Concentration of 1 x 10-9 mole per liter. Nucleus The organelle that houses the chromosomes. Organisms Plants, animals, and other forms of life that are made up of complex and interconnected systems of cells and tissue. Orphan receptor Receptor with unknown function binding known ligands. Pathogen Agent that causes disease, especially a micro-organism. PCR See Polymerase chain reaction Peptide Molecule consisting of 2 to approximately 20 amino acids; a short segment of a larger protein or a completely functional molecule unto itself. Pharmacokinetics Movements of drugs within biological systems, as affected by absorption, distribution, metabolism, excretion (ADME). Phase I Closely monitored clinical trial of a drug or vaccine conducted in a small number of healthy volunteers; used to determine toxicity, pharmacokinetics, preferred route of administration, and safe dosage range of a drug. Phase II Controlled clinical study of a drug or vaccine to identify common shortterm side effects and risks associated with the drug or vaccine, to collect information on its immunogenicity and to demonstrate its efficacy conducted on a limited number of patients Phase III Clinical studies involving a larger number of patients, designed to assess safety, effectiveness, and optimum dosage of a drug as administered in a treatment setting usually including several hundred to several thousand volunteers. Polymerase Any enzyme that catalyzes the formation of DNA or RNA from building blocks. Polymerase chain reaction (PCR) Method for amplifying (exponentially copying) a DNA molecule in vitro. Protease Any enzyme that catalyzes the cleavage of a peptide or protein. Protease inhibitors Class of drugs designed to inhibit the enzyme protease. Protein Large, complex molecule composed of amino acids. Proteins are essential to the structure, function, and regulation of the body. Examples are hormones, enzymes, and antibodies. Proteome Complete profile of all expressed (produced) proteins within a cell, a tissue, or an entire organism at a given time. Proteomics Analysis of the functions and interactions of proteins in healthy tissue compared to tissue affected by a disease. QSAR Quantitative structure activity relationship, statistical method of investigating three dimensional properties and biological activities of sets of molecules. Reagent Any chemical used in a laboratory test or experiment. Receptor Protein in a cell or on its surface that selectively binds a specific substance (ligand). Upon binding its ligand, the receptor triggers a specific response in the cell. Recombinant DNA molecules Combination of DNA molecules of different origin that are joined using recombinant DNA technologies. Recombinant DNA technologies Procedures used to join together DNA segments in vitro. RNA Ribonucleic acid: form of genetic information; takes part in translation of DNA into proteins. Screening Application of an established assay format to compound libraries in mass testing. Sequencing Process by which the order and identity of the molecular building blocks that comprise a DNA or protein molecule is determined. Side effect See adverse effect. Substrate Chemical compound that is recognized and modified by an enzyme. Subtractive analysis Description of a situation by finding the difference between two states, for example between healthy cells and the same cells affected by a disease. Syndrome Recognizable pattern or group of multiple signs, symptoms or malformations that characterize a particular condition. Target Specific biological molecule, such as an enzyme, receptor or ion channel, assumed to be relevant to a certain disease. Most drugs work by binding to a target, thereby affecting its biological function. Target identification Identifying a molecule (often a protein) that is instrumental to a disease process (though not necessarily directly involved), with the intention of finding a way to regulate that molecule’s activity for therapeutic purposes. Target validation Crucial step in the drug discovery process. Following the identification of a potential disease target, target validation verifies that a drug that specifically acts on the target can have a significant therapeutic benefit in the treatment of a given dise Toxicology Scientific discipline concerned with understanding the mechanisms by which chemicals produce noxious effects on living tissues or organisms. Translational diffusion Diffusion-induced movement of a molecule or particle along all three axes within a three-dimensional space. vHTS See virtual High Throughput Screening virtual High Throughput Screening (vHTS) Computer simulated screening of huge databases of molecules. Virtual library Database of a multitude of different molecules for virtual screening. Virus Infectious biological particle composed of a piece of genetic material – RNA or DNA – surrounded by a protein coat.