Lähdesmäki P, Karppinen A, Saarni H, Winter R
Brain Res. 1977 Dec 16;138(2):295-308. doi: 10.1016/0006-8993(77)90747-8.
A synaptic vesicle fraction was prepared from calf brain cortex, containing 10 identified amino acids and two unidentified ninhydrin-positive compounds, one of which is apparently a peptide. The most plentiful amino acids were taurine (1.8 nmol/g original tissue), glutamic acid (1.8), serine (0.9), aspartic acid (0.8) and GABA (0.8); the others identified were cysteic acid (or cysteinesulphinic acid), glutamine, alanine, glycine and lysine. The unknown peptide occurred in a high concentration (about 16 alanine equivalents/g), and contained mainly aspartic acid and serine. Cysteic acid (or cysteinesulphinic acid) also occurred in relatively high amounts, but its peak contained acid-labile impurities. The influx of [14C]glutamate into the vesicles took place by means of non-saturable migration, while two saturable systems having very similar properties were dominant only at low glutamate concentrations. Influx constants for these quantitatively low uptake systems were Km, 34 and 92 micrometer, and Vmax, 33 and 49 nmol/min/g obtained by v versus v/S plot. Almost the same values were also obtained by a 1/v versus 1/S plot. GAD and GABA-T activities in the vesicles were only 1/200th of those in the synaptosomes.
从小牛脑皮层制备了一种突触小泡组分，其中含有10种已鉴定的氨基酸和两种茚三酮阳性但未鉴定的化合物，其中一种显然是肽。含量最丰富的氨基酸是牛磺酸（1.8 nmol/g原始组织）、谷氨酸（1.8）、丝氨酸（0.9）、天冬氨酸（0.8）和GABA（0.8）；其他已鉴定的氨基酸是半胱磺酸（或半胱亚磺酸）、谷氨酰胺、丙氨酸、甘氨酸和赖氨酸。未知肽以高浓度存在（约16个丙氨酸当量/g），主要含有天冬氨酸和丝氨酸。半胱磺酸（或半胱亚磺酸）含量也相对较高，但其峰含有对酸不稳定的杂质。[14C]谷氨酸进入小泡是通过非饱和迁移进行的，而仅在低谷氨酸浓度下，两个性质非常相似的饱和系统占主导地位。通过v对v/S作图获得的这些定量上低摄取系统的流入常数为Km，34和92微米，Vmax，33和49 nmol/min/g。通过1/v对1/S作图也获得了几乎相同的值。小泡中的GAD和GABA-T活性仅为突触体中活性的1/200。
