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:1984
卷号:81
期号:14
页码:4404-4408
DOI:10.1073/pnas.81.14.4404
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:125I-labeled protein 4.1a and 4.1b have equal ability to reassociate with inside-out erythrocyte vesicles that were depleted of protein 4.1 in addition to other peripheral membrane proteins. The reassociation of 125I-labeled protein 4.1 to protein 4.1-depleted vesicles at 4 degrees C is salt dependent, pH dependent, and saturable with a Kd of 42-50 nM and an extrapolated maximal binding capacity of 120-140 micrograms of protein 4.1 bound per mg of vesicle protein or 60-70 micrograms of protein 4.1 bound per mg of ghost protein, correlating with the protein 4.1 content in the erythrocyte membrane (6-7% of the total membrane protein). Selective proteolytic cleavage of these vesicles with papain (5 micrograms/ml at 4 degrees C) eliminates greater than 60% of the high-affinity binding sites; therefore, we conclude that the interaction of protein 4.1 with the cytoplasmic membrane surface is through a specific high-affinity protein-protein association.