Phosphorylation heterogeneity of tryptic phosphopeptides of chicken riboflavin-binding protein.
The tryptic phosphopeptide of hen egg white riboflavin-binding protein has been found to exist as a mixture of peptides which differ only with respect to the number of covalently bound phosphoryl groups. Anion-exchange chromatography was used to separate homologues of the tryptic phosphopeptide of egg white riboflavin-binding protein. Four peptide peaks were obtained and analyzed using plasma desorption mass spectrometry. Molecular ions obtained agree closely with calculated molecular weight values for phosphopeptides with 8, 7 and 5 phosphoryl groups. Amino acid analyses showed that the octa- and hepta-phosphorylated peptides were pure and had the same amino acid compositions.
D000818:Animals; D002352:Carrier Proteins / Q000032:analysis*; D002645:Chickens; D004529:Egg White; D026901:Membrane Transport Proteins; D010446:Peptide Fragments / Q000032:analysis; D010750:Phosphoproteins / Q000032:analysis*; D012256:Riboflavin / Q000378:metabolism*; D014357:Trypsin
D002352:Carrier Proteins; D026901:Membrane Transport Proteins; D010446:Peptide Fragments; D010750:Phosphoproteins; C019079:riboflavin-binding protein; D014357:Trypsin; D012256:Riboflavin