title: Formation of a native-like beta-hairpin finger structure of a peptide from the extended PDZ domain of neuronal nitric oxide synthase in aqueous solution.
abstract: Neuronal nitric oxide synthase (nNOS) is targeted to the cell membrane via interactions of its extended PDZ domain with PDZ domains of membrane-associated proteins including PSD-95 and alpha1-syntrophin. The formation of heterodimers between the nNOS PDZ domain and the PDZ domains of nNOS-binding proteins requires a stretch of continuous amino-acid residues C-terminal to the canonical nNOS PDZ domain. In this work, we show that a 27-residue peptide comprising the C-terminal extension of the extended nNOS PDZ domain is capable of binding to PSD-95. The structure of the 27-residue peptide in aqueous solution was determined using multidimensional NMR-spectroscopic techniques. The free peptide adopts a native-like beta-hairpin finger structure in aqueous solution. The results indicate that the C-terminal extension peptide of the nNOS PDZ domain may represent a relatively independent structural unit in the mediation of the interaction between nNOS and PDZ domain-containing proteins including PSD-95 and alpha1-syntrophin.
authors.affiliation: Department of Biochemistry, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, P. R. China.
authors.forename: P
authors.initials: P
authors.lastname: Wang
authors.forename: Q
authors.initials: Q
authors.lastname: Zhang
authors.forename: H
authors.initials: H
authors.lastname: Tochio
authors.forename: J S
authors.initials: JS
authors.lastname: Fan
authors.forename: M
authors.initials: M
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019281:Dimerization; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009474:Neurons / Q000201:enzymology; D019001:Nitric Oxide Synthase / Q000737:chemistry*; D052248:Nitric Oxide Synthase Type I; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D051381:Rats; D012996:Solutions
chemical_list: D012996:Solutions; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496322:Nos1 protein, rat