菌類の蛋白分解酵素に関する研究 : (第2報) Aspergillus oryzaeのアルカリ性プロテアーゼに及ぼす種々の金属キレートの影響

概要

論文の詳細を見る
Factors affecting the inhibitory action of metal chelates of o-phenanthroline (Phen) on the alkaline protease produced by Aspergillus oryzae (APase) were investigated. Of various metal ions tested, bivalent copper, nickel, cobalt, zinc and cadmium chelates of Phen showed inhibitory effects on the caseinolytic activity of APase. However, its esterolytic activity of APase was potently inhibited only by Phen-Cu chelate, whereas other metal chelates hardly affected it. Phen-Fe(III) chelate, on the contrary, accelerated the esterase activity of the enzymes by about 40% at the final concentration of 5×10^<-4>M.Michaelis constants for benzoyl-_L-arginine ethyl ester (BAEE) and benzol-_L-tryosine ehtyl ester (BTEE)-hydrolyzing reaction of APase were calculated to be 7.9×10^<-3>M and 3.2×10^<-2>M, respectively. The nihibitor constants for Phen-Cu chelate on APase. the esterolytic activity of which was inhibited noncompetitively, were also estimated to be 4.8×10^<-7>M and 4.8×10^<-6>M with BAEE and BTEE (in 25% ethanol) as substrates, respectively.The logarithm of the concentrations of Phen-Cu, Ni, Zn, and Cd chelates changed linearly in accordance with their inhibitory abilities for the caseinolytic activity of APase and the most effective Phen-Cd chelate inhibited the enzyme by 20% even at the final concentration of 10^<-5>M.In view of the differences between the inhibitions of the caseinolytic and esterolytic activities of APase by various metal chelate, dependence of these inhibitions on the casein concentration and effects of these metal chelates on the thermostability of APase, that each metal chelate has its own characteristic mehanism in the inhibition of APase activities.Copper(II) chelate of neocuproin had less inhibitory effect on APase than that of Phen-Cu chelate because of the steric hindrance by two methyl groups existing on the same side of the nitrogen-nitrogen co-ordinate group of neocuproin.
社団法人日本生物工学会の論文
1969-07-25

菌類の蛋白分解酵素に関する研究 : (第2報) Aspergillus oryzaeのアルカリ性プロテアーゼに及ぼす種々の金属キレートの影響

スポンサーリンク

概要

著者

関連論文

スポンサーリンク