Mian N, Herries D G, Cowen D M, Batte E A
Biochim Biophys Acta. 1975 May 23;391(1):179-88. doi: 10.1016/0005-2744(75)90164-3.
K-m values of beta-N-acetylglucosaminidase (2-acetamido-2-deoxy-beta-D-glucoside acetamidodeoxyglucohydrolase EC 3.2.1.30), beta-N-acetylgalactosaminidase (EC 3.2.1.53), beta-galactosidase (beta-D-galactoside galactohydrolase EC 3.2.1.23) and alpha-L-fucosidase (alpha-L-fucoside fucohydrolase EC 3.2.1.51) of distal colonic tumours, induced in rats by 1,2-dimethylhydrazine, were found to be significantly different compared with the values for the enzymes of the colonic mucosa of the control and tumour-bearing animals and of the proximal colonic tumours. The inhibition kinetics data also showed a significant difference between the enzymes of the distal colon tumours and of other experimental tissues. The data on the effect of pH on enzyme kinetics (pK values) showed no significant difference in the catalytic groups of the active centres of enzymes from tumours and from the control colonic mucosa. Tumour beta-N-acetylglucosaminidase and beta-N-acetylgalactosaminidase compared with the enzymes from other experimental tissues were found to be different in their thermal inactivation kinetics. K-m values of 14 days old foetal intestinal beta-N-acetylglucosaminidase and beta-N-acetylgalactosaminidase were significantly different from the values obtained for the adult mucosal enzymes but were similar to those of the distal colonic tumour enzymes.
用1,2 - 二甲基肼诱导大鼠产生的远端结肠肿瘤中，β - N - 乙酰氨基葡萄糖苷酶（2 - 乙酰氨基 - 2 - 脱氧 - β - D - 葡萄糖苷乙酰氨基脱氧葡糖苷水解酶，EC 3.2.1.30）、β - N - 乙酰半乳糖苷酶（EC 3.2.1.53）、β - 半乳糖苷酶（β - D - 半乳糖苷半乳糖水解酶，EC 3.2.1.23）和α - L - 岩藻糖苷酶（α - L - 岩藻糖苷岩藻糖水解酶，EC 3.2.1.51）的米氏常数，与对照动物和荷瘤动物结肠黏膜以及近端结肠肿瘤中这些酶的值相比，存在显著差异。抑制动力学数据也表明，远端结肠肿瘤的酶与其他实验组织的酶之间存在显著差异。关于pH对酶动力学影响的数据（pK值）表明，肿瘤和对照结肠黏膜中酶活性中心催化基团没有显著差异。与其他实验组织的酶相比，肿瘤β - N - 乙酰氨基葡萄糖苷酶和β - N - 乙酰半乳糖苷酶在热失活动力学方面存在差异。14日龄胎儿肠道β - N - 乙酰氨基葡萄糖苷酶和β - N - 乙酰半乳糖苷酶的米氏常数与成年黏膜酶的值显著不同，但与远端结肠肿瘤酶的值相似。
