STOICHIOMETRY OF K+/H+ ANTIPORT HELPS TO EXPLAIN EXTRACELLULAR PH 11 IN A MODEL EPITHELIUM
STOICHIOMETRY OF K+/H+ ANTIPORT HELPS TO EXPLAIN EXTRACELLULAR PH 11 IN A MODEL EPITHELIUM
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DOI：
10.1016/0014-5793(95)00146-z
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发表时间：
1995-03-20
期刊：
影响因子：
3.5
通讯作者：
WIECZOREK, H
中科院分区：
文献类型：
--
作者：
AZUMA, M;HARVEY, WR;WIECZOREK, H
用静态头部荧光法测定了鳞翅目幼虫中肠杯状细胞顶膜高纯度囊泡中K+/H+逆向转运蛋白的化学计量比。测定的1 K+/2 H+的化学计量学解释了在位于同一膜上的H+转运V-ATPase的质子动力的电压分量的驱动下，反向通道如何导致细胞外H+与细胞内K+的电泳性交换。反过来，K+到H+的交换有助于解释中肠内容物是如何碱化到pH为11的。
The stoichiometry of K+/H+ antiport was measured fluorometrically by the static head method in highly purified vesicles from goblet cell apical membranes of larval lepidopteran midgut. The measured stoichiometry of 1 K+/2 H+ explains how the antiport results in electrophoretic exchange of extracellular H+ for intracellular K+, driven by the voltage component of the proton-motive force of an H+ translocating V-ATPase that is located in the same membrane. In turn, the exchange of K+ for H+ helps to explain how the midgut contents are alkalinized to a pH of 11.