title: Assignment of the aromatic 1H-NMR resonances of myotoxin a isolated from the venom of Crotalus viridis viridis.
abstract: The 400 MHz 1H-NMR spectrum of myotoxin a from the venom of Crotalus viridis viridis is described. The identification of spin systems in the aromatic region corresponding to the six aromatic residues of myotoxin a was completed using both one- and two-dimensional NMR spectroscopy and the pH dependence of chemical shifts. Assignments of these spin systems to specific residues was possible for the singly occurring amino acids Tyr-1 and Phe-12. Resonances from Tyr-1, His-5 and His-10 were shifted significantly from their random coil values in a pH-dependent manner. These shift perturbations were deemed evidence of a helical arrangement of the amino terminal region which placed these residues in close proximity to each other.
mesh_terms: D000818:Animals; D003435:Crotalid Venoms / Q000302:isolation & purification; D006639:Histidine / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D010649:Phenylalanine / Q000032:analysis; D011487:Protein Conformation; D012911:Snakes; D014443:Tyrosine / Q000032:analysis
chemical_list: D003435:Crotalid Venoms; D014443:Tyrosine; D010649:Phenylalanine; D006639:Histidine; C018932:myotoxin A