title: A proton nuclear magnetic resonance study on the solution structure of crotamine.
abstract: Proton nuclear magnetic resonance (NMR) spectra of crotamine, a myotoxic protein from a Brazilian rattlesnake (Crotalus durissus terrificus), have been analyzed. All the aromatic proton resonances have been assigned to amino acid types, and those from Tyr-1, Phe-12, and Phe-25 to the individual residues. The pH dependence of the chemical shifts of the aromatic proton resonances indicates that Tyr-1 and one of the two histidines (His-5 or His-10) are in close proximity. A conformational transition takes place at acidic pH, together with immobilization of Met-28 and His-5 or His-10. Two sets of proton resonances have been observed for Ile-17 and His-5 or His-10, which suggests the presence of two structural states for the crotamine molecule in solution.
authors.affiliation: Department of Chemistry, College of Technology, Gunma University, Kiryu, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Endo
authors.forename: M
authors.initials: M
authors.lastname: Oya
authors.forename: H
authors.initials: H
authors.lastname: Ozawa
authors.forename: Y
authors.initials: Y
authors.lastname: Kawano
authors.forename: J R
authors.initials: JR
authors.lastname: Giglio
authors.forename: T
authors.initials: T
authors.lastname: Miyazawa
mesh_terms: D000595:Amino Acid Sequence; D003435:Crotalid Venoms; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D011487:Protein Conformation; D012996:Solutions
chemical_list: D003435:Crotalid Venoms; D012996:Solutions; C018932:myotoxin A; C010563:crotamine