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，含有神经递质物质，在突触传递过程中通过胞吐释放。突触小泡的化学结构几乎还不清楚，除了突触素I，它与囊泡膜结合和解离，从而控制小泡与突触前细胞膜的融合。为了鉴定其他囊泡特异性蛋白，我们建立了从豚鼠大脑皮层纯化的突触囊泡部分的单抗文库。四组不同的抗体鉴定了四种囊泡特异性蛋白，分别为30、36、3和65千达。我们将它们命名为SVP(突触囊泡蛋白)30、36、38和65。与突触素I不同的是，SVPs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的免疫组织化学研究表明，在中枢和外周神经系统中突触的发育和组织有多个方面。例如，在小脑中证实了各种突触的发育时间进程。SVP在突触传递中的生理作用有待于进一步阐明。

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.