Disulfide bonds in recombinant human platelet-derived growth factor BB dimer: characterization of intermolecular and intramolecular disulfide linkages.
Interchain cystines of PDGF-BB dimer were characterized by Edman reaction and by SDS-PAGE analysis on the protein which was chemically cleaved at Trp-40. It was found that Cys-43 has a key role in dimer formation, asymmetrically cross-linked to a cysteine residue of another identical subunit. The remaining cystines participate in the intramolecular disulfide linkages. Pepsin digestion of PDGF-BB dimer generated several small peptides and one ubiquitous Cys-containing peptide. Sequence analyses of several Cys-containing peptides indicated the existence of three intramolecular disulfide linkages including Cys-16--Cys-60, Cys-49--Cys-97, and Cys-53--Cys-99. Two interchain disulfide bonds of Cys-43--Cys-52 between two subunits were deduced from the partial reduction and alkylation of PDGF-BB. This study provides chemically determined disulfide linkages of PDGF-BB.
Haniu
M
M
Department of Protein Structure, Amgen Inc., Thousand Oaks, California 91320.
Rohde
M F
MF
Kenney
W C
WC
D000107:Acetylation; D000478:Alkylation; D000595:Amino Acid Sequence; D000077214:Becaplermin; D003545:Cysteine / Q000032:analysis; D004220:Disulfides / Q000737:chemistry*; D006801:Humans; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010446:Peptide Fragments / Q000737:chemistry; D010982:Platelet-Derived Growth Factor / Q000737:chemistry*; D011487:Protein Conformation; D020574:Proto-Oncogene Proteins c-sis; D011994:Recombinant Proteins / Q000737:chemistry*
D004220:Disulfides; D010446:Peptide Fragments; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D011994:Recombinant Proteins; D000077214:Becaplermin; D003545:Cysteine