由人类galactosylceramidase lactosylceramide水解和GM1-beta-galactosidase不用洗涤剂的系统及其刺激的鞘脂类催化剂蛋白质,sap-B sap-C。激活蛋白刺激lactosylceramide水解。
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如Zschoche,福斯特W, Schwarzmann G, Sanhoff K
由人类galactosylceramidase lactosylceramide水解和GM1-beta-galactosidase不用洗涤剂的系统及其刺激的鞘脂类催化剂蛋白质,sap-B sap-C。激活蛋白刺激lactosylceramide水解。
5月15日。1994欧元;222 (1):83 - 90。doi: 10.1111 / j.1432-1033.1994.tb18844.x。
- PubMed ID
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8200356 (在PubMed]
- 文摘
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两个exo-beta-galactosidases参与鞘糖脂的溶酶体降解:GM1-beta-galactosidase (EC 3.2.1.23)和galactosylceramidase (EC 3.2.1.46)。分析与这两种酶,用lactosylceramides不同酰基链长度作为基质,插入单膜脂质体和天然蛋白质鞘脂类活化剂sap-B sap-C,而不是洗涤剂,刺激反应。当sap-B GM1-beta-galactosidase更好的反应催化剂催化,sap-C优先刺激lactosylceramide galactosylceramidase水解。的酶水解liposome-integrated lactosylceramides明显依赖于结构的亲脂性的糖苷配基的一部分lactosylceramide随长度增加的脂酰链(C2 > C4 > C6 > C8 > C10 > C18)。然而,在洗涤剂降解率的存在独立的酰基链的长度。水解的脂质体lactosylceramide与sap-B-stimulated水解脂质体的神经节苷脂GM1 GM1-beta-galactosidase和sap-C-stimulated退化的脂质体galactosylceramide galactosylceramidase。动能和稀释实验表明sap-B水溶性复合物lactosylceramide和GM1形式。这些复合物被GM1-beta-galactosidase公认为最优基质在相同的模式中,作为假设硫苷脂的水解arylsulfatase(费舍尔,g . Jatzkewitz, h (1977) Biochim。Biophys。481年学报,561 - 572]。 GM1-beta-galactosidase was more active on these complexes than on glycolipids (GM1 and lactosylceramides) still residing in liposomal membranes. On the other hand, dilution experiments indicated that degradation of galactosylceramide and lactosylceramide by galactosylceramidase proceeds almost exclusively on liposomal surfaces: both activators, sap-C and sap-B, stimulated the hydrolysis of lactosylceramide analogues with long acyl chains more than the hydrolysis of lactosylceramides with short acyl chains.