Orlacchio A, Emiliani C, Di Renzo G C, Cosmi E V
Clin Chim Acta. 1986 Sep 30;159(3):279-89. doi: 10.1016/0009-8981(86)90061-6.
Two beta-N-acetylglucosaminidase isoenzymes (A and B) have been identified and purified from amnionic fetal membrane. The final specific activity of A and B isoenzymes increased 225- and 185-fold respectively by a purification scheme, which included a lyophilized extract, chromatofocusing on PBE 94, pH range 5.5 to 4.0, and affinity chromatography on p-aminophenyl-2-acetamido-2-deoxy-1-thio-beta-D-glucopyranoside covalently linked to Sepharose-4B. Different electrophoretic mobility, thermostability and different thiol group modifications of the two isoenzymes were found. Acetate was a more effective competitive inhibitor than were iodoacetamide, N-acetylglucosamine and N-acetylgalactosamine more than glucosamine and galactosamine, confirming a specific 'acetamido receptor site' for both the isoenzymes.
已从羊膜胎儿膜中鉴定并纯化出两种β-N-乙酰氨基葡萄糖苷酶同工酶（A和B）。通过一种纯化方案，A和B同工酶的最终比活性分别提高了225倍和185倍，该方案包括冻干提取物、在pH范围为5.5至4.0的PBE 94上进行色谱聚焦以及在与琼脂糖-4B共价连接的对氨基苯基-2-乙酰氨基-2-脱氧-1-硫代-β-D-吡喃葡萄糖苷上进行亲和色谱。发现这两种同工酶具有不同的电泳迁移率、热稳定性以及不同的巯基修饰。乙酸盐是比碘乙酰胺更有效的竞争性抑制剂，N-乙酰氨基葡萄糖和N-乙酰半乳糖胺比葡萄糖胺和半乳糖胺更有效，这证实了两种同工酶都有一个特定的“乙酰氨基受体位点”。
