TEMPERATURE-DEPENDENT CHANGES OF CHLORIDE TRANSPORT KINETICS IN HUMAN RED-CELLS
TEMPERATURE-DEPENDENT CHANGES OF CHLORIDE TRANSPORT KINETICS IN HUMAN RED-CELLS
复制标题
DOI：
10.1085/jgp.70.3.283
复制
发表时间：
1977-01-01
影响因子：
3.8
通讯作者：
BRAHM, J
中科院分区：
文献类型：
--
作者：
BRAHM, J
研究了人红细胞中的氯离子自交换在0 ℃和0 ℃之间。C和38度。C.在较高温度下，使用流管法。虽然一般特点的氯离子运输在0。C和38度。温度从0 ℃升高时，氯离子自交换通量的最大pH值从7.8降低到7.2，降低了0.6个pH单位。38度。表观半饱和常数从0 ℃时的28 mM增加到0 ℃时的28 mM。在38 ℃至65 mM。在体温下的氯离子转运比其他研究者根据低温结果外推的预测要慢。当温度从0 ℃升高时，氯离子转运仅增加200倍。38度。这是因为在高于15 ℃的温度下，表观活化能从30 kcal mol-1降低到20 kcal mol-1。较慢的溴化物自交换的温度依赖性的研究表明，活化能的类似变化发生在25 ℃左右。C.在Cl-（15 ° C）的情况下，C）和在Br-（25 ° C）的情况下，C）时，当阴离子自交换具有约4. 109离子细胞-1s-1; DIDS（4，4“-二异硫氰基-芪-2，2”-二磺酸盐）对氯离子转运的抑制显示偏转持续在15 °。C在部分抑制（66%），大概是因为DIDS失活66%的运输网站。温度依赖性较小的阴离子交换步骤在达到临界转换数的温度下可能成为速率限制。
Chloride self-exchange in human red cells was studied between 0.degree. C and 38.degree. C. At higher temperatures the flow-tube method was used. Although the general features of chloride transport at 0.degree. C and 38.degree. C are similar, the following differences were found: the maximum pH of chloride self-exchange flux was lowered 0.6 pH unit from 7.8 to 7.2 when temperature was increased from 0.degree. C to 38.degree. C; the apparent half-saturation constant increased from 28 mM at 0.degree. C to 65 mM at 38.degree. C; chloride transport at body temperature is slower than predicted by other investigators by extrapolation from low-temperature results. Chloride transport increased only 200 times when temperature was raised from 0.degree. C to 38.degree. C, because the apparent activation energy decreased from 30 kcal mol-1 to 20 kcal mol-1 above a temperature of 15.degree. C; a study of temperature dependence of the slower bromide self-exchange showed that a similar change of activation energy occurred around 25.degree. C. Both in the case of Cl- (15.degree. C) and in the case of Br- (25.degree. C), critical temperature was reached when the anion self-exchange had a turnover number of about 4 .cntdot. 109 ions cell-1 s-1; inhibition of chloride transport by DIDS (4,4''-diisothiocyano-stilbene-2,2''-disulfonate) revealed that the deflection persisted at 15.degree. C at partial inhibition (66%) presumably because DIDS inactivated 66% of the transport sites. A less temperature-dependent step of anion exchange may become rate limiting at the temperature where a critical turnover number is reached.