Glutathione transport by inside-out vesicles from human erythrocytes.
Glutathione transport by inside-out vesicles from human erythrocytes.
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谷胱甘肽通过人红细胞由内而外的囊泡转运。
DOI：
10.1073/pnas.77.11.6359
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发表时间：
1980
影响因子：
11.1
通讯作者：
Beutler,E
中科院分区：
文献类型：
--
作者：
Kondo,T;Dale,GL;Beutler,E
用纯化的人红细胞内向外的囊泡研究了氧化谷胱甘肽(GSSG)的主动转运。囊泡和GSSG在ATP存在下孵育后，GSSG被转运到囊泡中。当囊泡与还原型谷胱甘肽(GSH)孵育时，没有观察到转运。当GSSG浓度小于5 mM时，在37℃下4小时内传输呈线性。传输速率随GSSG浓度变化的Lineweaver-Burk图为双相图，表观Km值分别为0.1和7.1 mm。ATP的公里数。在此传输过程中，GSSG浓度为20微米时的镁为0.63 mm，GSSG浓度为5 mM时为1.25 mm。低浓度GSSG的转运速率可被CTP或UTP所抑制，它们是ATP的竞争性抑制剂，Ki=0.51 mM。这种抑制可能是在嘧啶-5‘-核苷酸酶缺乏症中观察到的红细胞GSH水平高的原因，这是一种红细胞CTP和UTP水平升高的疾病。
Purified inside-out vesicles from human erythrocytes were used to investigate the active transport of oxidized glutathione (GSSG). Incubation of vesicles and GSSG in the presence of ATP resulted in the transport of GSSG into the vesicles. When vesicles were incubated with reduced glutathione (GSH), no transport was observed. At GSSG concentrations of less than 5 mM, transport was linear up to 4 hr at 37 degrees C. A Lineweaver-Burk plot of the transport rate as a function of GSSG concentration was biphasic and gave apparent Km values of 0.1 and 7.1 mM. The Km for ATP . Mg in this transport process was 0.63 mM at a GSSG concentration of 20 microM and 1.25 mM at a GSSG concentration of 5 mM. The transport rate at low GSSG concentrations was inhibited by CTP or UTP, which acted as competitive inhibitors of ATP; Ki=0.51 mM. This inhibition may account for the high erythrocyte GSH levels observed in pyrimidine-5'-nucleotidase deficiency, a disorder in which erythrocytic levels of CTP and UTP are elevated.