L-lysine uptake in giant vesicles from cardiac ventricular sarcolemma: two components of cationic amino acid transport.
L-lysine uptake in giant vesicles from cardiac ventricular sarcolemma: two components of cationic amino acid transport.
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心室肌膜巨型囊泡中 L-赖氨酸的摄取：阳离子氨基酸转运的两个组成部分。
DOI：
10.1042/bsr20080159
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发表时间：
2009
影响因子：
4
通讯作者：
Peluffo,RDaniel
中科院分区：
文献类型：
--
作者：
Lu,Xiaodong;Zheng,Ruifang;Gonzalez,Jorge;Gaspers,Lawrence;Kuzhikandathil,Eldo;Peluffo,RDaniel
阳离子氨基酸通过载体介导的转运进入心肌细胞。为了详细研究这一过程，在103倍的L-赖氨酸浓度范围内，进行了大鼠心脏巨大肌膜小泡摄取L-[14C]赖氨酸的实验。囊泡的表面积体积比与上皮细胞的表面积体积比相当，因此是研究初始摄取率的合适系统。发现两个Na+非依赖的N-乙基马来酰亚胺敏感摄取组分，一个具有高表观亲和力(Km=2 2 2±71μM)和低转运能力(Vmax=12 1±36 pmoL/m in/mg囊泡蛋白)，另一个低表观亲和力(Km=16±4 mm)和高容量(Vmax=4.0±0.4nmol/m in/mg囊泡蛋白)。总之，这种行为与阳离子氨基酸转运体系统y+家族中CAT-1和CAT-2A成员的功能特性是一致的。此外，在新鲜分离的大鼠心肌细胞中发现了这两种载体蛋白的转录产物，CAT-1mRNA的量相对于β-肌动蛋白的量是CAT-2A的33倍。这两种转运蛋白似乎同时起着平衡装置的作用，在各种代谢条件下为心肌细胞提供阳离子氨基酸。对两个载体与这样一系列动力学参数并行作用的分析表明，即使在远低于其Km的氨基酸血浆水平上，低亲和力成分也具有显著的活性。
CationicL-amino acids enter cardiac-muscle cells through carrier-mediated transport. To study this process in detail,L-[14C]lysine uptake experiments were conducted within a 103-fold range ofL-lysine concentrations in giant sarcolemmal vesicles prepared from rat cardiac ventricles. Vesicles had a surface-to-volume ratio comparable with that of an epithelial cell, thus representing a suitable system for initial uptake rate studies. Two Na+-independent,N-ethylmaleimide-sensitive uptake components were found, one with high apparent affinity (Km=222±71 μM) and low transport capacity (Vmax=121±36 pmol/min per mg of vesicle protein) and the other with low apparent affinity (Km=16±4 mM) and high capacity (Vmax=4.0±0.4 nmol/min per mg of vesicle protein).L-Lysine uptake mediated by both components was stimulated by the presence of intravesicularL-lysine as well as by valinomycin-induced membrane hyperpolarization. Altogether, this behaviour is consistent with the functional properties of the CAT-1 and CAT-2A members of the system y+family of cationic amino acid transporters. Furthermore, mRNA transcripts for these two carrier proteins were identified in freshly isolated rat cardiac myocytes, the amount of CAT-1 mRNA, relative to β-actin, being 33-fold larger than that of CAT-2A. These two transporters appear to function simultaneously as a homoeostatic device that supplies cardiac-muscle cells with cationic amino acids under a variety of metabolic conditions. Analysis of two carriers acting in parallel with such an array of kinetic parameters shows significant activity of the low-affinity component even at amino acid plasma levels far below itsKm.
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阳离子氨基酸转运至培养的动物细胞中。
影响因子：
4.8
作者：
M. F. White;G. Gazzola;H. Christensen
通讯作者：
H. Christensen
L-精氨酸的流入是人成纤维细胞膜电位的指标。
影响因子：
--
作者：
O. Bussolati;P. C. Laris;F. Nucci;V. Dall’Asta;R. Franchi‐Gazzola;G. Guidotti;G. Gazzola
通讯作者：
G. Gazzola
肾脏代偿性生长期间肾脏和血浆氨基酸浓度的变化。
影响因子：
--
作者：
F. Toback;A. Mayers;L. Lowenstein
通讯作者：
L. Lowenstein
兔网织红细胞中的阳离子氨基酸转运。
DOI：
10.1016/s0021-9258(18)91787-4
发表时间：
1969
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
H. Christensen;J. Antonioli
通讯作者：
J. Antonioli
阳离子氨基酸转运至培养的动物细胞中。
影响因子：
4.8
作者：
M. F. White;H. Christensen
通讯作者：
H. Christensen