Shigeta S, Kubota H, Tamura H, Oka S
J Biochem. 1983 Dec;94(6):1827-32. doi: 10.1093/oxfordjournals.jbchem.a134535.
An alpha-mannosidase was isolated from the extract of acetone powder of CHCl3-treated internal organs of the sea-squirt, Styela plicata. The enzyme was purified 4,110-fold in 11% yield. The preparation was fairly homogeneous on disc and SDS-polyacrylamide gel electrophoreses and Sephadex G-200 chromatography. The enzyme had an estimated molecular weight of 275,000 by gel chromatography and 70,000 by SDS-polyacrylamide gel electrophoresis, and was therefore considered to be a tetramer. The optimum pH for the enzyme activity was 3.4 but the stable pH range was from 4 to 6. The isoelectric point was 5.0. The enzyme was activated by Zn2+ but inhibited by Cu2+, Fe2+, Hg2+, and EDTA. The isolated enzyme released mannose not only from stem bromelin glycopeptide and ovalbumin glycopeptide but also from yeast mannan.
从经氯仿处理的皱瘤海鞘内脏丙酮粉提取物中分离出一种α-甘露糖苷酶。该酶经纯化后，比活力提高了4110倍，产率为11%。通过圆盘电泳、SDS-聚丙烯酰胺凝胶电泳和Sephadex G-200柱层析分析，该酶制品相当纯。凝胶过滤法测得该酶的分子量约为275,000，SDS-聚丙烯酰胺凝胶电泳法测得其分子量为70,000，因此认为它是一种四聚体。该酶的最适pH为3.4，但稳定的pH范围是4至6。其等电点为5.0。该酶被Zn2+激活，但被Cu2+、Fe2+、Hg2+和EDTA抑制。分离出的这种酶不仅能从菠萝蛋白酶糖肽和卵清蛋白糖肽中释放甘露糖，还能从酵母甘露聚糖中释放甘露糖。
