LaBelle E F, Singh S V, Ahmad H, Wronski L, Srivastava S K, Awasthi Y C
Department of Human Biological Chemistry and Genetics, University of Texas Medical Branch, Galveston 77550.
FEBS Lett. 1988 Feb 8;228(1):53-6. doi: 10.1016/0014-5793(88)80583-0.
Vesicles prepared from human erythrocyte membranes were found to catalyze ATP hydrolysis that was stimulated by dinitrophenylglutathione (Dnp-SG). This activity was dependent on temperature and Mg2+ and independent of ion pump ATPases present in erythrocyte membranes. The activity was a linear function of protein and time up to 60 min. The Km values of ATPase for Dnp-SG and ATP were found to be 49 microM and 1.67 mM, respectively. This suggests that in erythrocytes, the transport of Dnp-SG requires direct enzymatic hydrolysis of ATP and both Dnp-SG-stimulated ATPase activity and the ATP-dependent efflux of Dnp-SG from erythrocytes represent different activities of the same protein.
研究发现，由人红细胞膜制备的囊泡能够催化ATP水解，该过程受到二硝基苯基谷胱甘肽（Dnp-SG）的刺激。这种活性依赖于温度和Mg2+，且与红细胞膜中存在的离子泵ATP酶无关。在长达60分钟的时间内，该活性是蛋白质和时间的线性函数。ATP酶对Dnp-SG和ATP的Km值分别为49 microM和1.67 mM。这表明在红细胞中，Dnp-SG的转运需要ATP的直接酶促水解，且Dnp-SG刺激的ATP酶活性以及Dnp-SG从红细胞中的ATP依赖外排代表了同一蛋白质的不同活性。
