A novel fragmentation of human myelin basic protein: identification of phosphorylated domains.
Human myelin basic protein (MBP) was fragmented into three major polypeptides comprised of a NH2-terminal domain (residues 1-83), a middle domain (residues 84-119) which contains an experimental allergic encephalitogenic determinant and a highly conserved triproline sequence, and a COOH-terminal domain (residues 120-170) by Staphylococcus aureus V8 protease at pH 4.0. These three polypeptides could be identified and purified by reversed-phase high-performance liquid chromatography. Analysis of the sites of phosphorylation of the component 1 of human MBP, the most cationic species, catalyzed by a purified Ca2+-activated and phospholipid-dependent protein kinase and cAMP-dependent protein kinase revealed that although these protein kinases could incorporate approximately 6 and 4 mol 32P, respectively, into MBP, none of the potential sites were located within the middle domain.
D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D008970:Molecular Weight; D004676:Myelin Basic Protein / Q000302:isolation & purification; D010446:Peptide Fragments / Q000032:analysis; D010748:Phosphopeptides / Q000032:analysis; D010766:Phosphorylation; D011493:Protein Kinase C / Q000302:isolation & purification; D011494:Protein Kinases / Q000302:isolation & purification
D004676:Myelin Basic Protein; D010446:Peptide Fragments; D010748:Phosphopeptides; D011494:Protein Kinases; D011493:Protein Kinase C