Hiraiwa M, Nishizawa M, Uda Y, Nakajima T, Miyatake T
Department of Health Chemistry, Niigata College of Pharmacy.
J Biochem. 1988 Jan;103(1):86-90. doi: 10.1093/oxfordjournals.jbchem.a122245.
An acid sialidase [EC 3.2.1.18] has been purified from human placenta by means of successive procedures including extraction, Con A-Sepharose adsorption, ammonium sulfate precipitation, activation, p-aminophenyl thio-beta-D-galactoside-CH-Sepharose (PATG-Sepharose) affinity chromatography and high-performance liquid chromatography on a Shim pack Diol 300 column. The purified enzyme liberated sialic acid residues from sialooligosaccharides, sialoglycoproteins, and gangliosides. In particular, gangliosides GM3, GD1a, and GD1b were hydrolyzed much faster than alpha (2-3) and alpha (2-6)sialyllactoses, and sialoglycoproteins by the enzyme. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the purified enzyme gave five protein bands with molecular weight of 78,000 (78K), 64,000 (64K), 46,000 (46K), 30,000 (30K), and 20,000 (20K). Rabbit antisera were raised against 78K and 46K proteins, and the two antibodies were specifically reactive with the respective component on immunoblot analysis. Both anti-78K protein and anti-46K protein antisera could precipitate sialidase activity. It is likely that the 78K protein and 46K protein are sub-components which are essential for sialidase activity.
一种酸性唾液酸酶[EC 3.2.1.18]已通过包括提取、伴刀豆球蛋白A-琼脂糖吸附、硫酸铵沉淀、活化、对氨基苯基硫代-β-D-半乳糖苷-CH-琼脂糖（PATG-琼脂糖）亲和层析以及在Shim pack Diol 300柱上进行高效液相色谱等一系列步骤从人胎盘中纯化出来。纯化后的酶能从唾液寡糖、唾液糖蛋白和神经节苷脂中释放出唾液酸残基。特别是，神经节苷脂GM3、GD1a和GD1b被该酶水解的速度比α(2-3)和α(2-6)唾液乳糖以及唾液糖蛋白快得多。在十二烷基硫酸钠-聚丙烯酰胺凝胶电泳上，纯化后的酶呈现出五条蛋白带，分子量分别为78,000（78K）、64,000（64K）、46,000（46K）、30,000（30K）和20,000（20K）。针对78K和46K蛋白制备了兔抗血清，在免疫印迹分析中这两种抗体分别与各自的组分发生特异性反应。抗78K蛋白和抗46K蛋白抗血清都能沉淀唾液酸酶活性。78K蛋白和46K蛋白可能是唾液酸酶活性所必需的亚组分。
