Photolabeling of calmodulin with basic, amphiphilic alpha-helical peptides containing p-benzoylphenylalanine.
A novel photoreactive amino acid has been incorporated synthetically into two model peptides and the calmodulin-binding domain from myosin light chain kinase. Cross-linked photoadducts of each peptide with calmodulin have been prepared and digested by chemical and/or enzymatic methods to determine the site of label attachment. Depending on the position of the photoprobe in the peptide sequence, either Met-144 or Met-71 is photolabeled. These results are discussed in relation to the three-dimensional structure of calmodulin obtained crystallographically and the known solution properties of calmodulin.
E. I. du Pont de Nemours & Company, Central Research and Development Department, Wilmington, Delaware 19880-0328.
K T
KT
O'Neil
S
S
Erickson-Viitanen
W F
WF
DeGrado
D000345:Affinity Labels; D000595:Amino Acid Sequence; D000818:Animals; D001667:Binding, Competitive; D002147:Calmodulin / Q000378:metabolism*; D002148:Calmodulin-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D002417:Cattle; D006868:Hydrolysis; D007700:Kinetics; D008666:Metalloendopeptidases; D008969:Molecular Sequence Data; D009219:Myosin-Light-Chain Kinase / Q000378:metabolism; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000378:metabolism; D010649:Phenylalanine / Q000031:analogs & derivatives*; D010777:Photochemistry / Q000379:methods; D011487:Protein Conformation
D000345:Affinity Labels; D002147:Calmodulin; D002148:Calmodulin-Binding Proteins; D010446:Peptide Fragments; D010649:Phenylalanine; C053764:benzoylphenylalanine; D009219:Myosin-Light-Chain Kinase; D008666:Metalloendopeptidases; C022653:auR protein, Staphylococcus aureus