SYNAPTOSOMAL PLASMA-MEMBRANE TRANSPORT OF EXCITATORY SULFUR AMINO-ACID TRANSMITTER CANDIDATES - KINETIC CHARACTERIZATION AND ANALYSIS OF CARRIER SPECIFICITY
SYNAPTOSOMAL PLASMA-MEMBRANE TRANSPORT OF EXCITATORY SULFUR AMINO-ACID TRANSMITTER CANDIDATES - KINETIC CHARACTERIZATION AND ANALYSIS OF CARRIER SPECIFICITY
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DOI：
10.1002/jnr.490320108
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发表时间：
1992-05-01
影响因子：
4.2
通讯作者：
GRIFFITHS, R
中科院分区：
文献类型：
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作者：
GRIEVE, A;BUTCHER, SP;GRIFFITHS, R
用高效液相色谱法研究了兴奋性含硫氨基酸（SAA）递质候选物L-半胱氨酸亚磺酸盐（L-CSA）、L-半胱氨酸酸盐（L-CA）、L-高半胱氨酸亚磺酸盐（L-HCSA）和L-高半胱氨酸酸盐（L-HCA）在皮层突触体组分中的转运动力学及其质膜载体特异性。可以证明L-CSA（K（m）= 57 +/- 6-μ-M; V（max）= 1.2 +/- 0.1 nmol/min/mg蛋白质）和L-CA（K（m）= 23 +/- 3-μ-M; V（max）= 3.6 +/- 0.1 nmol/min/mg蛋白质）的高亲和力摄取系统，而L-HCSA（K（m）= 502 +/- 152-μ-M; V（max）= 6.1 +/- 1.3 nmol/min/mg蛋白质）和L-HCA（K（m）= 1550 +/- 169 μ-M; V（max）= 10.3 +/- 1.1 nmol/min/mg蛋白质）作为转运底物表现出低得多的亲和力。在所有情况下，只有一个单一的，饱和的Na+依赖性的吸收组件可以确定，共存的非饱和，Na+非依赖性流入组件。质膜载体特异性的SAA建立与其他高亲和力的神经递质系统进行比较。高亲和力L-CSA和L-CA转运与低亲和力L-HCSA和L-HCA转运在相互比较或单独与L-[H-3]谷氨酸、L-[H-3]天冬氨酸或D-[H-3]天冬氨酸的高亲和力转运进行比较时，显示出抑制曲线的强正相关性。此外，运输系统的兴奋性SAA表现出负相关性时，在抑制曲线与高亲和力运输的[H-3] γ-氨基丁酸（GABA）和[H-3]牛磺酸。总之，这些结果强烈表明，L-CSA，L-CA，L-HCSA和L-HCA与L-谷氨酸，L-天冬氨酸和D-天冬氨酸共享共同的突触体质膜转运系统。
The transport kinetics of the excitatory sulphur-containing amino acid (SAA) transmitter candidates, L-cysteine sulphinate (L-CSA), L-cysteate (L-CA), L-homocysteine sulphinate (L-HCSA), and L-homocysteate (L-HCA), together with their plasma membrane carrier specificity, was studied in cerebrocortical synaptosome fractions by a sensitive high performance liquid chromatographic assay. A high affinity uptake system could be demonstrated for L-CSA (K(m) = 57 +/- 6-mu-M; V(max) = 1.2 +/- 0.1 nmol/min/mg protein) and L-CA (K(m) = 23 +/- 3-mu-M; V(max) = 3.6 +/- 0.1 nmol/min/mg protein), whereas L-HCSA (K(m) = 502 +/- 152-mu-M; V(max) = 6.1 +/- 1.3 nmol/min/mg protein) and L-HCA (K(m) = 1550 +/- 169-mu-M; V(max) = 10.3 +/- 1.1 nmol/min/mg protein) exhibited much lower affinity as transport substrates. In all cases, only a single, saturable Na+-dependent component of uptake could be identified, co-existing with a non-saturable, Na+-independent influx component. Plasma membrane carrier specificity of the SAAs was established following comparison with other high-affinity neurotransmitter systems. High-affinity L-CSA and L-CA transport and low-affinity L-HCSA and L-HCA transport demonstrate strong positive correlations in inhibition profiles when compared against each other or individually against the high-affinity transport of L-[H-3]glutamate, L-[H-3]aspartate, or D-[H-3]aspartate. Moreover, the transport systems for the excitatory SAAs exhibited a negative correlation when compared in inhibition profiles with the high affinity transport of both [H-3] gamma-aminobutyric acid (GABA) and [H-3]taurine. Taken together, these results strongly suggest that L-CSA, L-CA, L-HCSA, and L-HCA share a common synaptosomal plasma membrane transport system with L-glutamate, L-aspartate, and D-aspartate.