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：1982
卷号：79
期号：3
页码：941-945
DOI：10.1073/pnas.79.3.941
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Dicyclohexylcarbodiimide (DCCD) is known to bind preferentially to a proteolipid subunit of proton-translocating systems and thereby to inhibit proton transport. In the present study we show that, in an aqueous medium, DCCD binds to the bovine white matter proteolipid apoprotein, the major protein of central nervous system myelin. The binding is dependent on time, temperature, and concentration and is not inhibited by the hydrophilic carbodiimide 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide. By contrast, when the incubation is carried out in chloroform/methanol no labeling by DCCD is demonstrable. In isolated rat myelin, DCCD binds specifically to the proteolipid and not to the myelin basic proteins. Liposomes reconstituted with the myelin proteolipid apoprotein transport protons, as assayed by quenching of the fluorescence of 9-aminoacridine. Preincubation of proteolipid-containing liposomes with DCCD results in an inhibition of transport. These studies have important implications for a possible ionophoric function of the myelin proteolipid and for the occurrence of transport processes within myelin.
