Fox J A, Duszenko M, Ferguson M A, Low M G, Cross G A
J Biol Chem. 1986 Nov 25;261(33):15767-71.
A novel membrane-bound glycan-phosphatidylinositol-specific phospholipase C, which catalyzes the conversion of membrane form variant surface glycoproteins to soluble variant surface glycoproteins, with the release of sn-1,2-dimyristylglycerol, has been isolated from Trypanosoma brucei. The activity was solubilized from trypanosome membrane fractions in non-ionic detergent and purified by anion exchange chromatography on DEAE-cellulose followed by chromatography on phosphatidylinositol-Sepharose. The enzyme constitutes about 0.1% of the total cellular protein and has an apparent molecular weight of 39,800. The enzyme shows a head group specificity for molecules containing carbohydrate covalently linked to glycan-phosphatidylinositol, but can also act on the monoacyl derivative of membrane form variant surface glycoprotein. It shows no specific ion requirements but is stimulated by thiol-reducing agents and inhibited by ions that thiols chelate.
从布氏锥虫中分离出一种新型的膜结合聚糖磷脂酰肌醇特异性磷脂酶C，它催化膜形式的可变表面糖蛋白转化为可溶性可变表面糖蛋白，并释放出sn-1,2-二肉豆蔻酰甘油。该酶活性可在非离子去污剂中从锥虫膜组分中溶解出来，并通过DEAE-纤维素阴离子交换色谱法，随后在磷脂酰肌醇-琼脂糖上进行色谱法纯化。该酶约占细胞总蛋白的0.1%，表观分子量为39,800。该酶对含有与聚糖磷脂酰肌醇共价连接的碳水化合物的分子表现出头部基团特异性，但也可作用于膜形式可变表面糖蛋白的单酰基衍生物。它没有特定的离子需求，但受到硫醇还原剂的刺激，并被硫醇螯合的离子抑制。
