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:1990
卷号:87
期号:14
页码:5523-5527
DOI:10.1073/pnas.87.14.5523
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:Twenty-three of the 25 cysteine residues in apolipoprotein B-100 have been isolated directly from tryptic or peptic peptide mixtures. Sixteen cysteine residues exist in disulfide forms: Cys-1-Cys-3, Cys-2-Cys-4, Cys-5-Cys-6, Cys-7-Cys-8, Cys-9-Cys-10, Cys-11-Cys-12, Cys-13-Cys-14, and Cys-20-Cys-21. All of these except Cys-20-Cys-21 are recently discovered disulfide linkages. In addition to Cys-22 and Cys-24, which have been described as sulfhydryls on low density lipoprotein, Cys-15 to Cys-18 and Cys-23 are in the reduced form. Cys-19 and Cys-25 are not yet confirmed. Our results revealed that all identified disulfide linkages are located in the trypsin-releasable regions and that all except Cys-1-Cys-3 and Cys-2-Cys-4 are linked to the neighboring cysteine. We propose a linear model of apolipoprotein B-100 in low density lipoprotein that wraps around the low density lipoprotein molecule.