期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1973
卷号：70
期号：3
页码：653-657
DOI：10.1073/pnas.70.3.653
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：3-O-methylglucose (3-OMeG) is a non-metabolizable glucose analog and is, therefore, suitable for transport studies. 3-OMeG and glucose compete for entry into normal and Rous sarcoma virus (RSV)-transformed chick-embryo fibroblasts. Therefore, 3-OMeG can be used to study the transport of glucose in these cells. Chick-embryo fibroblasts infected and transformed by RSV take up 3-OMeG at a faster rate than uninfected cells when both cell types are growing at the same rate. The rate of efflux of 3-OMeG also increases after transformation. When the uptake and the efflux reach a steady state, the intracellular concentration of 3-OMeG is equal to the concentration in the medium. This finding indicates that glucose is transported across the plasma membrane by facilitated diffusion. The Vmax of the transport system for 3-OMeG increases after transformation, while the affinity or Km of the system remains unchanged. We conclude that viral transformation causes a change in the plasma membrane of the infected cells by increasing either the number of molecules or the mobility of the glucose carrier.
关键词：3- O -methylglucose ; glucose ; competition ; efflux ; facilitated diffusion ; Km , V max
