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In biochemistry, suicide inhibition, also known as suicide inactivation or mechanism-based inhibition, is an irreversible form of enzyme inhibition that occurs when an enzyme binds a substrate analogue and forms an irreversible complex with it through a covalent bond ''during the "normal" catalysis reaction''. The inhibitor binds to the active site where it is modified by the enzyme to produce a reactive group that reacts irreversibly to form a stable inhibitor-enzyme complex. This usually uses a prosthetic group or a coenzyme, forming electrophilic alpha and beta unsaturated carbonyl compounds and imines. ==Examples== Some clinical examples of suicide inhibitors include: * Aspirin, which inhibits cyclooxygenase 1 and 2 enzymes. * Penicillin, which inhibits DD-transpeptidase from building bacterial cell walls. * Sulbactam, which prohibits penicillin-resistant strains of bacteria from metabolizing penicillin. * Allopurinol, which inhibits uric acid production by xanthine oxidase in the treatment of gout. * AZT (zidovudine) and other chain-terminating nucleoside analogues used to inhibit HIV-1 reverse transcriptase in the treatment of HIV/AIDS. * Eflornithine, one of the drugs used to treat sleeping sickness, is a suicide inhibitor of ornithine decarboxylase. * Sarin is a suicide inhibitor of acetylcholinesterase. *5-fluorouracil acts as a suicide inhibitor of thymidylate synthase during the synthesis of thymine from uridine. This reaction is crucial for the proliferation of cells, particularly those that are rapidly proliferating (such as fast-growing cancer tumors). By inhibiting this step, cells die from a thymineless death because they have no thymine to create more DNA. This is often used in combination with Methotrexate, a potent inhibitor of dihydrofolate reductase enzyme. *Exemestane, a drug used in the treatment of breast cancer, is an inhibitor of the aromatase enzyme. *Selegiline, although in the attached reference the compound is called a 'suicide inactivator' (not inhibitor). *Vigabatrin, an anticonvulsant, is a suicide inhibitor of GABA-T. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Suicide inhibition」の詳細全文を読む スポンサード リンク
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