Identification of synaptic vesicle-specific proteins and their physiological roles in synaptic transmission

突触囊泡聚集在突触前神经末梢内，并含有在突触传递期间通过胞吐作用释放的神经递质物质。突触囊泡的化学结构仍然几乎是未知的，除了突触蛋白I，它与囊泡膜结合并解离，从而控制囊泡与突触前细胞膜的融合。为了鉴定其他囊泡特异性蛋白，我们制备了一个从豚鼠大脑皮层纯化的突触囊泡组分的单克隆抗体库。四组不同的抗体鉴定了30、36、3和65千道尔顿的四种囊泡特异性蛋白。我们将它们命名为SVP（synaptic vesicle protein）30、36、38和65。与突触蛋白I不同，SVP整合在囊泡膜内。SVP 65在钙存在下被磷酸化。SVP 38被认为与在西德国和美国独立发现的突触素和p38相同。用抗SVP抗体对哺乳动物神经组织进行免疫组织化学研究，证实了中枢和外周神经系统突触发育和组织的几个方面。例如，在小脑中证实了各种突触发育的时间过程。SVP在突触传递中的生理作用有待进一步阐明。

Synaptic vesicles are clustered within the presynaptic nerve terminals and contain neurotransmitter substances which are released via exocytosis during the synaptic transmission. Chemical architecture of the synaptic vesicles remains almost unknown except for synapsin I which is associated and dissociated with the vesicle membrane and thus controls fusion of the vesicles with the presynaptic cell memmbrane. In order to identify other vesicle-specific proteins, we produced a library of monoclonal antibodies against synaptic vesicle fraction purified from the guinea pig cerebral cortex. Four different groups of the antibodies identified four vesicle specific proteins of 30, 36, 3, and 65 kilodalons. We named them SVP (synaptic vesicle protein) 30, 36, 38 and 65. Unlike synapsin I, SVPs were integrated within the vesicle membrane. SVP 65 were phosphorylated in the presence of calcium. SVP 38 was considered to be identical with synaptophysin and p38 which were independently discovered in West germany and the United States. Immunohistochemistry of the mammalisn nervous tissue with anti-SVP antibodies has demonstrated several aspects in development and organization of the synapses in the central and peripheral nervous system. For exzmple, time course of development of various synapses was confirmed in the cerebellum. Physiological roles of the SVPs in the synaptic transmission remain to be elucidated in future.