Sequence of a benzyladenine binding site peptide isolated from a wheat embyro cytokinin-binding protein

摘要: A wheat embryo cytokinin-binding protein (CBF-1) was covalently modified with the radiolabeled photoaffinity ligand (/sup 14/C)-2-azido-N/sup 6/-benzyladenine (AzBA). single labeled peptide obtained after proteolytic digestion and isolation by reversed-phase anion exchange HPLC. Sequencing Edman degradation identified 11 of 12 residues, but failed to identify amino acid. Amino acid analysis sequencing laser photodissociation-Fourier transform mass spectrometry conclusively residue as histidine: Ala-Phe-Leu-Gln-Pro-Ser-His-His*-Asp-Ala-Asp-Glu. Comparison this sequence known partial primary CBF-1 (determined tandem quadrupole spectrometry) showed that there were two homologous sequences in CBF-1. One exactly matched above AzBA other differed a substitution tyrosine for second histidine. The possibility binding non-binding isomers will be discussed along proposed model BA binding.