关于环己酰亚胺在体外对骆驼视网膜乙酰胆碱酯酶活性的抑制作用。

On the inhibition of camel retina acetylcholinesterase activity by cycloheximide in vitro.

作者信息

al-Jafari A A, Kamal M A, Alhomida A S

机构信息

Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia.

出版信息

Cell Biol Toxicol. 1998 Jun;14(3):167-74. doi: 10.1023/a:1007421124793.

DOI:10.1023/a:1007421124793

PMID:9689490

Abstract

The kinetic parameters of inhibition of camel retinal acetylcholinesterase (AChE) activity by cycloheximide (CH) were investigated. For the control system, the Michaelis-Menten constant (K(m)) for the hydrolysis of acetylthiocholine iodide was found to be 0.076 mmol/L and the Vmax was 0.547 mumol/min per mg protein. In contrast, these parameters were decreased in the CH-treated systems. Dixon and Lineweaver-Burk plots, and their secondary replots, indicated that the inhibition was of the linear mixed type, which seems to be a combination of partial competitive and pure noncompetitive inhibition. The values of K'i(slope) and KI(intercept) were estimated to be 3.50 and 5.68 mmol/L, respectively. Ki was greater than K'i, indicating that CH has a greater binding affinity for the peripheral site than the active site.

摘要

研究了环己酰亚胺（CH）对骆驼视网膜乙酰胆碱酯酶（AChE）活性抑制的动力学参数。对于对照系统，发现碘化硫代乙酰胆碱水解的米氏常数（K(m)）为0.076 mmol/L，Vmax为每毫克蛋白质0.547 μmol/min。相比之下，在CH处理的系统中这些参数降低。Dixon和Lineweaver-Burk图及其二次重绘图表明抑制作用为线性混合型，这似乎是部分竞争性抑制和纯非竞争性抑制的组合。K'i（斜率）和KI（截距）的值分别估计为3.50和5.68 mmol/L。Ki大于K'i，表明CH对外周位点的结合亲和力大于活性位点。