Determination of the DNA sequences of acetylcholinesterase and butyrylcholinesterase from cat and demonstration of the existence of both in cat plasma

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• 作者：Bartels ; Cynthia F. ; Xie ; Weihua ; Miller-Lindholm ; Amanda K. ; Schopfer ; Lawrence M. ; Lockridge ; Oksana
• 关键词：feline ; Felis ; cholinesterase ; acetylcholinesterase
• 刊名：Biochemical Pharmacology
• 出版年：2000
• 出版时间：August 15, 2000
• 年：2000
• 卷：60
• 期：4
• 页码：479-487
• 全文大小：295 K

文摘

Cat serum contains 0.5 mg/L of butyrylcholinesterase (BChE, EC 3.1.1.8) and 0.3 mg/L of acetylcholinesterase (AChE, EC 3.1.1.7); this can be compared with 5 mg/mL and < 0.01 mg/L, respectively, in human serum. Cat BChE differed from human BChE in the steady-state turnover of butyrylthiocholine, having a 3-fold higher k_cat and 2-fold higher K_m and K_ss values. Sequencing of the cat BCHE cDNA revealed 70 amino acid differences between cat and human BChE, three of which could account for these kinetic differences. These amino acids, which were located in the region of the active site, were Phe398Ile, Pro285Leu, and Ala277Leu (where the first amino acid was found in human and the second in cat). Sequencing genomic DNA for cat and human ACHE demonstrated that there were 33 amino acid differences between the cat and human AChE enzymes, but that there were no differences in the active site region. In addition, a polymorphism in intron 3 of the human ACHE gene was detected, as well as a silent polymorphism at Y116 of the cat ACHE gene.