Eksittikul T, Chulavatnatol M
Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, Thailand.
Arch Biochem Biophys. 1988 Oct;266(1):263-9. doi: 10.1016/0003-9861(88)90257-3.
Linamarase (EC 3.2.1.21) was purified from cassava petiole, stem, and root cortex by ammonium sulfate precipitation, column chromatography on Sepharose 6B, and chromatofocusing. The last step resolved the enzyme from each source into three forms with pI values of 4.3, 3.3, and 2.9. Each form was found to be oligomeric, consisting of one kind of subunit, Mr 63,000. The major isozyme with a pI of 4.3 from petiole showed a Km for linamarin of 0.6 mM and possessed both beta-glucosidase and beta-fucosidase activities. The former was sensitive to inhibition by delta-gluconolactone, isopropyl-beta-D-thioglucoside, and HgCl2, whereas the latter was inhibited by Tris ion.
从木薯叶柄、茎和根皮层中通过硫酸铵沉淀、Sepharose 6B柱色谱和色谱聚焦法纯化了亚麻苦苷酶（EC 3.2.1.21）。最后一步将来自每种来源的酶解析为三种形式，其pI值分别为4.3、3.3和2.9。发现每种形式都是寡聚体，由一种亚基组成，Mr为63,000。叶柄中pI为4.3的主要同工酶对亚麻苦苷的Km为0.6 mM，同时具有β-葡萄糖苷酶和β-岩藻糖苷酶活性。前者对δ-葡萄糖酸内酯、异丙基-β-D-硫代葡萄糖苷和HgCl2的抑制敏感，而后者受Tris离子抑制。
