Identification of thiol groups and a disulfide crosslink site in bovine myelin proteolipid protein

FEBS Letters

Shaw, Shyh-Yu²  Laursen, Richard A.²  Lees, Marjorie B.¹ 

[1] E.K. Shriver Center, Waltham, MA 02254, USA;Department of Chemistry, Boston University, Boston, MA 02215 USA

关键词: Myelin proteolipid protein;    Lipophilin;    Polypeptide conformation;    Disulfide bond;    Membrane protein topology;    CAM-;    carboxamidomethyl-;    CM-Cys;    carboxymethylcysteine;    PLP;    myelin proteolipid protein;    HPLC;    high-performance liquid chromatography;    PTH;    phenylthiohydantoin;    Tris;    tris-(hydroxymethyl)aminomethane;   

DOI  :  10.1016/0014-5793(89)80744-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The existence of disulfide crosslinks limits the number of possible folded structures a protein can assume. Thus localization of disulfide and thiol groups is a key to understanding the conformation and orientation of myelin proteolipid protein (PLP) in the myelin membrane. [¹⁴C]Carboxamidomethylated PLP was fragmented with chymotrypsin, and the resulting mixture was partially separated by reversed-phase HPLC. Purified ¹⁴C-labeled peptides and a disulfide containing peptide were characterized by amino acid analysis. These experiments showed that Cys-32 and Cys-34 are free thiols, and are presumably on the interior of the cell or within the membrane bilayer, and that Cys-200 and Cys-219 are joined by a disulfide bond, and are probably located on the extracellular face of the membrane. Sequence analysis experiments indicate that Cys-5, Cys-6 and Cys-9 are linked by disulfides, probably to other parts of the protein on the extracellular face of the membrane.

【 授权许可】

Unknown