Tsyperovich A S, Surgova T M
Ukr Biokhim Zh. 1976 Sep-Oct;48(5):587-91.
The activity and stability of some enzymes of Asp. awamori cellulolytic complex were studied as affected by chemical modification of carboxylic groups with N,N'-dicyclohexyl carbodiimide (DCCD) and amine groups with glutaric aldehyde. The carboxylic groups are established to be necessary for manifestation of the activities of C1- and C2-cellulases, Cx-exo- and Cx-endoglucanases. Their role is negligible in the action of beta-glucosidase. The activity of individual cellulases was studied as affected by nucleophilic substitution of DCCD-activated COOH-groups by various reagents (glycine amide, leucine amide, tyrosine amide and N-benzoyl-l-arginine-methyl ether-hydrochloride). Tyrosine amide is the least inacting reagent for all the enzymes, glycine amide is somewhat more activating. Essential differences are shown in the chemical and catalytic properties of Cx-exoglucanase and beta-glucosidase. It is found (under the effect of glutaric aldehyde) that amino groups are significant for manifestation of the activities of C1- and C2-cellulases and Cx-endoglucanase and to a less extent for that of Cs-exoglucanase and beta-glucosidase. It is supposed that electrostatic interactions of the carbolytic and amine groups might be an essential factor for stability of C1- and C2-cellulases and Cx-endoglucanase.
研究了用N，N'-二环己基碳二亚胺（DCCD）对羧基进行化学修饰以及用戊二醛对氨基进行化学修饰时，泡盛曲霉纤维素分解复合体某些酶的活性和稳定性受到的影响。已确定羧基对于C1和C2纤维素酶、外切Cx和内切Cx葡聚糖酶活性的表现是必需的。它们在β-葡萄糖苷酶的作用中作用可忽略不计。研究了用各种试剂（甘氨酰胺、亮氨酰胺、酪氨酰胺和N-苯甲酰-L-精氨酸甲酯盐酸盐）对DCCD活化的COOH基团进行亲核取代时，各个纤维素酶的活性受到的影响。酪氨酰胺对所有酶的作用最小，甘氨酰胺的激活作用稍强一些。外切Cx葡聚糖酶和β-葡萄糖苷酶在化学和催化性质上表现出本质差异。发现（在戊二醛的作用下）氨基对于C1和C2纤维素酶以及内切Cx葡聚糖酶活性的表现很重要，对外切Cs葡聚糖酶和β-葡萄糖苷酶活性表现的重要性稍低。据推测，羧基和氨基的静电相互作用可能是C1和C2纤维素酶以及内切Cx葡聚糖酶稳定性的一个重要因素。
