大黄鱼肌肉胆碱酯酶的生化特性

Biochemical properties of a cholinesterase from muscles of Pseudosciaena crocea

观察了亲和层析纯化的大黄鱼肌肉胆碱酿酶与抑制剂和底物的反应。该酶显示乙酰胆碱酪酶（ＥＣ．３．１．１．７）和丁酰胆碱酯酶（ＥＣ．３．１．１．８）的双重特征，它对毒扁豆碱十分敏感。碘化硫代乙酰胆碱和碘化硫代丁酰胆碱对该酶均有底物抑制效应，乙酰胆碱酿酶特异性抑制剂ＢＷ２８４Ｃ５１对该酶抑制作用明显，丁酰胆碱酯酶抑制剂四异丙基焦磷酰胺的抑制作用较差．

The reactions of acholinesterase(ChE)purified by afflnity chromatography from themusclcs ofPsEUdosciaena crocea with some inhibitors and substrates were investigated. The enzvme showedsome properties typical for an acetylcholinesterase(AChE EC.3.1.1.7)and others typical for a butyrylcholinesterase (BChE EC.3.1.1.8).The highsensitivity to physostigmine characterizes the enzymeinvestigated as a ChE. It does display a substrate inhibi-tion with acetylthiocholine iodide (ATCh)andbutyrylthiocholine iodide(BTCh) By measuring the ac-tivities of thes fnzyme both with ATCh and BTCh.it is found that they are very sensitive to the action ofBW284C51 [1,5-bis-(4-allyldimethylammoniumphenyl)pentan 3-one-dibromide], a specific inhibitor ofAChE,while it is not sensitive to iso-OMPA(tetraisopropylpyrophosphoramide),a sDecificinbibitor of BChE.