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:1974
卷号:71
期号:12
页码:5032-5036
DOI:10.1073/pnas.71.12.5032
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:Transport of vinylglycolate (2-hydroxy-3-butenoic acid) via the lactate transport system is the limiting step for covalent labeling of membrane vesicles prepared from E. coli ML 308-225. Thus, the rate and extent of vinylglycolate labeling is stimulated about 10-fold by ascorbate-phenazine methosulfate, and stimulation is abolished by 2,4-dinitrophenol and by phospholipase treatment, neither of which affect the rate of vinylglycolate oxidation. [3H]Vinylglycolate of high specific activity has been prepared, and vesicles have been labeled with this compound in the presence of ascorbate-phenazine methosulfate. Examination of these preparations by high resolution radioautography in the electron microscope demonstrates that virtually all of the vesicles are labeled. The experiments provide a strong indication that most, if not all, of the membrane vesicles in these preparations catalyze active transport.
关键词:vinylglycolate ; 2-hydroxy-3-butenoate ; D-lactate ; radioautography ; electron microscopy