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Characterization of a benzyladenine binding-site peptide isolated from a wheat cytokinin-binding protein: Sequence analysis and identification of a single affinity-labeled histidine residue by mass spectrometry

Journal Article · · Proceedings of the National Academy of Sciences of the United States of America; (USA)
A wheat embryo cytokinin-binding protein was covalently modified with the radiolabeled photoaffinity ligand 2-azido-N{sup 6}-({sup 14}C)benzyladenine. A single labeled peptide was obtained after proteolytic digestion and isolation by reversed-phase and anion-exchange HPLC. Sequencing by classical Edman degradation identified 11 of the 12 residues but failed to identify the labeled amino acid. Analysis by laser photodissociation Fourier-transform mass spectrometry of 10 pmol of the peptide independently confirmed the Edman data and also demonstrated that the histidine residue nearest the C terminus (underlined) was modified by the reagent in the sequence Ala-Phe-Leu-Gln-Pro-Ser-His-His{und His}-Asp-Ala-Asp-Glu.
OSTI ID:
5517444
Journal Information:
Proceedings of the National Academy of Sciences of the United States of America; (USA), Journal Name: Proceedings of the National Academy of Sciences of the United States of America; (USA) Vol. 85:16; ISSN 0027-8424; ISSN PNASA
Country of Publication:
United States
Language:
English