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Chemical Probe
In the field of chemical biology, a chemical probe is a small molecule that is used to study and manipulate a biological system such as a cell or an organism by reversibly binding to and altering the function of a biological target (most commonly a protein) within that system. Probes ideally have a high affinity and binding selectivity for one protein target as well as high efficacy. By changing the phenotype of the cell, a molecular probe can be used to determine the function of the protein with which it interacts. See also * Chemical Probes Portal The Chemical Probes Portal is an open, online resource whose purpose is to identify and make available high quality chemical probes for use in biological research and drug discovery. While chemical probes can be valuable tools to elucidate sig ... References {{reflist Chemical biology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Biology
Chemical biology is a scientific discipline spanning the fields of chemistry and biology. The discipline involves the application of chemical techniques, analysis, and often small molecules produced through synthetic chemistry, to the study and manipulation of biological systems. In contrast to biochemistry, which involves the study of the chemistry of biomolecules and regulation of biochemical pathways within and between cells, chemical biology deals with chemistry ''applied to'' biology (synthesis of biomolecules, the simulation of biological systems, etc.). Introduction Some forms of chemical biology attempt to answer biological questions by studying biological systems at the chemical level. In contrast to research using biochemistry, genetics, or molecular biology, where mutagenesis can provide a new version of the organism, cell, or biomolecule of interest, chemical biology probes systems ''in vitro'' and ''in vivo'' with small molecules that have been designed for a specific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Small Molecule
Within the fields of molecular biology and pharmacology, a small molecule or micromolecule is a low molecular weight (≤ 1000 daltons) organic compound that may regulate a biological process, with a size on the order of 1 nm. Many drugs are small molecules; the terms are equivalent in the literature. Larger structures such as nucleic acids and proteins, and many polysaccharides are not small molecules, although their constituent monomers (ribo- or deoxyribonucleotides, amino acids, and monosaccharides, respectively) are often considered small molecules. Small molecules may be used as research tools to probe biological function as well as leads in the development of new therapeutic agents. Some can inhibit a specific function of a protein or disrupt protein–protein interactions. Pharmacology usually restricts the term "small molecule" to molecules that bind specific biological macromolecules and act as an effector, altering the activity or function of the target. Small ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell (biology)
The cell is the basic structural and functional unit of life forms. Every cell consists of a cytoplasm enclosed within a membrane, and contains many biomolecules such as proteins, DNA and RNA, as well as many small molecules of nutrients and metabolites.Cell Movements and the Shaping of the Vertebrate Body in Chapter 21 of Molecular Biology of the Cell '' fourth edition, edited by Bruce Alberts (2002) published by Garland Science. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos. It is also common to describe small molecules such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Target
A biological target is anything within a living organism to which some other entity (like an endogenous ligand or a drug) is directed and/or binds, resulting in a change in its behavior or function. Examples of common classes of biological targets are proteins and nucleic acids. The definition is context-dependent, and can refer to the biological target of a pharmacologically active drug compound, the receptor target of a hormone (like insulin), or some other target of an external stimulus. Biological targets are most commonly proteins such as enzymes, ion channels, and receptors. Mechanism The external stimulus (''i.e.'', the drug or ligand) physically binds to ("hits") the biological target. The interaction between the substance and the target may be: * noncovalent – A relatively weak interaction between the stimulus and the target where no chemical bond is formed between the two interacting partners and hence the interaction is completely reversible. * reversible covalent â ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ligand (biochemistry)
In biochemistry and pharmacology, a ligand is a substance that forms a complex with a biomolecule to serve a biological purpose. The etymology stems from ''ligare'', which means 'to bind'. In protein-ligand binding, the ligand is usually a molecule which produces a signal by binding to a site on a target protein. The binding typically results in a change of conformational isomerism (conformation) of the target protein. In DNA-ligand binding studies, the ligand can be a small molecule, ion, or protein which binds to the DNA double helix. The relationship between ligand and binding partner is a function of charge, hydrophobicity, and molecular structure. Binding occurs by intermolecular forces, such as ionic bonds, hydrogen bonds and Van der Waals forces. The association or docking is actually reversible through dissociation. Measurably irreversible covalent bonding between a ligand and target molecule is atypical in biological systems. In contrast to the definition of lig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binding Selectivity
Binding selectivity is defined with respect to the binding of ligands to a substrate forming a complex. Binding selectivity describes how a ligand may bind more preferentially to one receptor than another. A selectivity coefficient is the equilibrium constant for the reaction of displacement by one ligand of another ligand in a complex with the substrate. Binding selectivity is of major importance in biochemistry and in chemical separation processes. Selectivity coefficient The concept of selectivity is used to quantify the extent to which one chemical substance, A, binds each of two other chemical substances, B and C. The simplest case is where the complexes formed have 1:1 stoichiometry. Then, the two interactions may be characterized by equilibrium constants ''K''AB and ''K''AC.The constant used here are ''association'' constants. ''Dissociation'' constants are used in some contexts. A dissociation constant is the reciprocal of an association constant. : + B AB; \mathit K_ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intrinsic Activity
Intrinsic activity (IA) and efficacy refer to the relative ability of a drug-receptor complex to produce a maximum functional response. This must be distinguished from the affinity, which is a measure of the ability of the drug to bind to its molecular target, and the EC50, which is a measure of the potency of the drug and which is proportional to both efficacy and affinity. This use of the word "efficacy" was introduced by Stephenson (1956) to describe the way in which agonists vary in the response they produce, even when they occupy the same number of receptors. High efficacy agonists can produce the maximal response of the receptor system while occupying a relatively low proportion of the receptors in that system. There is a distinction between efficacy and intrinsic activity. Mechanism of efficacy Agonists of lower efficacy are not as efficient at producing a response from the drug-bound receptor, by stabilizing the active form of the drug-bound receptor. Therefore, they ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Probes Portal
The Chemical Probes Portal is an open, online resource whose purpose is to identify and make available high quality chemical probes for use in biological research and drug discovery. While chemical probes can be valuable tools to elucidate signal transduction pathways and to validate new drug targets, many of the probes that are in use are not selective and therefore can give very misleading results. The Portal recommends chemical probes based on ratings provided by its Scientific Advisory Board (SAB), a group of experts in the fields of chemical biology, medicinal chemistry, and pharmacology, who (1) determine which are the best chemical probes available and (2) establish guidelines for using them. History After years of publishing best practice guidelines for the selection and use of chemical probes, many in the field agreed that publications were insufficient to disseminate this type of information. In July 2015, these experts, led by the Structural Genomics Consortium ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
