Reglero A, Cabezas J A
Eur J Biochem. 1976 Jul 1;66(2):379-87. doi: 10.1111/j.1432-1033.1976.tb10527.x.
An alpha-L-fucosidase had been purified approximately 300-fold from the liver (hepatopancreas) of the marine mollusc Chamelea gallina L. (= Venus gallina L.). During the different steps of the purification procedure it was difficult to remove the contaminant N-acetylglucosaminidase activity; but, after electrofocusing, a final preparation free of this and other glycosidades present in the crude extract was obtained. The purified enzyme has a broad specificity; it hydrolyzes p-nitrophenyl alpha-L-fucoside and natural substrates such as oligosaccharides containing fucosidic residues with alpha 1--2, alpha 1--3 and alpha 1--4 linkages; also it hydrolyzes fucose-containing glycopeptides, such as thyroglobulin glycopeptide, and glycoproteins as procine submaxillary mucin (previously rendered free of sialic acid). The enzyme has a pH optimum of 5.2 +/- 0.2, with a Km of 7 X 10(-5) M using p-nitrophenyl L-fucoside as substrate. It is inhibited by Hg2+ and some sugars, and activated by CN-, Zn2+, Ca2+ and EDTA. It shows two peaks by isoelectric focusing (at 6.3 and 6.6). The molecular weight of the alpha-L-fucosidase by gel filtration was over 2000000.
已从海洋软体动物加利福尼亚变色龙（= 金星变色龙）的肝脏（肝胰腺）中纯化出一种α-L-岩藻糖苷酶，纯化倍数约为300倍。在纯化过程的不同步骤中，很难去除污染物N-乙酰葡糖胺酶的活性；但是，经过等电聚焦后，获得了一种不含粗提物中存在的这种和其他糖苷酶的最终制剂。纯化后的酶具有广泛的特异性；它能水解对硝基苯基α-L-岩藻糖苷和天然底物，如含有α1--2、α1--3和α1--4键的含岩藻糖残基的寡糖；它还能水解含岩藻糖的糖肽，如甲状腺球蛋白糖肽，以及糖蛋白，如猪颌下粘蛋白（先前已去除唾液酸）。该酶的最适pH为5.2 +/- 0.2，以对硝基苯基L-岩藻糖苷为底物时的Km为7×10^(-5) M。它受到Hg2+和一些糖类的抑制，并被CN-、Zn2+、Ca2+和EDTA激活。通过等电聚焦显示有两个峰（在6.3和6.6处）。通过凝胶过滤法测得α-L-岩藻糖苷酶的分子量超过2000000。
