Proton NMR resonance assignments and surface accessibility of tryptophan residues of a dimeric phospholipase A2 from Trimeresurus flavoviridis.
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.
Endo
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Department of Chemistry, College of Technology, Gunma University, Kiryu, Japan.
Oya
M
M
Kaptein
R
R
Vuister
G W
GW
Kihara
H
H
Mohri
N
N
Tanaka
S
S
Ohno
M
M
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
D046911:Macromolecular Substances; D012910:Snake Venoms; D012996:Solutions; D014364:Tryptophan; D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2