title: Proton NMR resonance assignments and surface accessibility of tryptophan residues of a dimeric phospholipase A2 from Trimeresurus flavoviridis.
abstract: Proton NMR spectra of a dimeric phospholipase A2 from Trimeresurus flavoviridis have been recorded. N-1 proton resonances of the tryptophan indole rings have been detected and assigned to specific positions, Trp-3/Trp-30, Trp-68 and Trp-108, by comparing the spectra of the enzyme derivatives with tryptophans oxidized to differing extents. Photo-CIDNP experiments have revealed that Trp-68 and Trp-108 are exposed while Trp-3 and Trp-30 are buried in the molecule. This is consistent with the X-ray crystal structure of a homologous phospholipase A2 from Crotalus atrox where residues 3 and 30 are located at a dimer interface, but inconsistent with the results of stepwise oxidation of tryptophan residues.
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: R
authors.initials: R
authors.lastname: Kaptein
authors.forename: G W
authors.initials: GW
authors.lastname: Vuister
authors.forename: H
authors.initials: H
authors.lastname: Kihara
authors.forename: N
authors.initials: N
authors.lastname: Mohri
authors.forename: S
authors.initials: S
authors.lastname: Tanaka
authors.forename: M
authors.initials: M
authors.lastname: Ohno
mesh_terms: D046911:Macromolecular Substances; D009682:Magnetic Resonance Spectroscopy; D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2; D010777:Photochemistry; D012910:Snake Venoms / Q000032:analysis*; D012996:Solutions; D013057:Spectrum Analysis; D014364:Tryptophan
chemical_list: D046911:Macromolecular Substances; D012910:Snake Venoms; D012996:Solutions; D014364:Tryptophan; D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2