Gundersen C B, Mastrogiacomo A, Faull K, Umbach J A
Department of Molecular and Medical Pharmacology, UCLA School of Medicine 90024.
J Biol Chem. 1994 Jul 29;269(30):19197-9.
Cysteine string proteins are relatively low mass components of synaptic vesicle membranes. Structurally, their primary sequence is distinguished by a remarkable, cysteine-rich motif. Investigations revealed an unprecedented degree of lipidation of these cysteine residues. At least 11 of the 13 cysteines of the Torpedo protein were modified, principally by palmitoyl moieties. This fatty acylation creates a prominent hydrophobic domain flanked by polar amino and carboxyl termini. An amphipathic structure of this type is uniquely suited to mediate events at membrane interfaces. Thus, cysteine string proteins are candidates to participate in exocytotic membrane fusion.
半胱氨酸串珠蛋白是突触小泡膜中相对低分子量的成分。在结构上，它们的一级序列以一个显著的富含半胱氨酸的基序为特征。研究揭示了这些半胱氨酸残基前所未有的脂酰化程度。电鳐蛋白的13个半胱氨酸中至少有11个被修饰，主要是被棕榈酰基部分修饰。这种脂肪酰化产生了一个由极性氨基和羧基末端包围的突出的疏水结构域。这种类型的两亲结构特别适合介导膜界面处的事件。因此，半胱氨酸串珠蛋白是参与胞吐膜融合的候选者。
