title: Characterization of novel calmodulin-binding peptides with distinct inhibitory effects on calmodulin-dependent enzymes.
abstract: We describe the isolation and interaction with calmodulin (CaM) of two 10-amino-acid peptides (termed peptides 1 and 2; AWDTVRISFG and AWPSLQAIRG respectively) derived from a phage random peptide display library. Both peptides are shorter than previously described CaM-binding peptides and lack certain features found in the sequences of CaM-binding domains present in CaM-activated enzymes. However, 1H NMR spectroscopy and fluorimetry indicate that both peptides interact with CaM in the presence of Ca2+. The two peptides differentially inhibited CaM-dependent kinases I and II (CaM kinases I and II) but did not affect CaM-dependent phosphodiesterase. Peptide 1 inhibited CaM kinase I but not CaM kinase II, whereas peptide 2 inhibited CaM kinase II, but only partially inhibited CaM kinase I at a more than 10-fold higher concentration. Peptide 1 also inhibited a plant calcium-dependent protein kinase, whereas peptide 2 did not. The ability of peptides 1 and 2 to differentially inhibit CaM-dependent kinases and CaM-dependent phosphodiesterase suggests that they may bind to distinct regions of CaM that are specifically responsible for activation of different CaM-dependent enzymes.
authors.affiliation: Laboratory of Plant Molecular Biology, Rocketeller University, New York, NY 10021, USA.
authors.forename: L T
authors.initials: LT
authors.lastname: Nevalainen
authors.forename: T
authors.initials: T
authors.lastname: Aoyama
authors.forename: M
authors.initials: M
authors.lastname: Ikura
authors.forename: A
authors.initials: A
authors.lastname: Crivici
authors.forename: H
authors.initials: H
authors.lastname: Yan
authors.forename: N H
authors.initials: NH
authors.lastname: Chua
authors.forename: A C
authors.initials: AC
authors.lastname: Nairn
mesh_terms: D000818:Animals; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors*; D002147:Calmodulin / Q000378:metabolism; D002148:Calmodulin-Binding Proteins / Q000737:chemistry*; D002417:Cattle; D054677:Cyclic Nucleotide Phosphodiesterases, Type 1; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009491:Neurospora; D010449:Peptide Mapping; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013737:Testis / Q000737:chemistry
chemical_list: D002147:Calmodulin; D002148:Calmodulin-Binding Proteins; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D010727:Phosphoric Diester Hydrolases; D054677:Cyclic Nucleotide Phosphodiesterases, Type 1