title: Conformational interpretation of intramolecular electron transfer in Met5-enkephalins between Tyr and Met(S:.Br) radical.
abstract: Mean distances between C beta atoms of redox centers and mean values of the exponentially distance dependent rate constants for intramolecular electron transfer, (k), in aqueous solution were calculated for Met5-enkephalin and its D-Ala2 analogue using the molecular mechanics and Monte Carlo techniques. The ratio of (k) values thus obtained proved similar to that determined experimentally for intramolecular electron transfer accompanying Met(S:.Br)----TyrO.radical transformation in these two peptides. This agreement indicates that the almost 2-fold difference observed between experimental k values for Met5-enkephalin and its D-Ala2 analogue can be attributed to the effect of Gly2 for D-Ala2 replacement on the average separation of the redox centers.
authors.affiliation: Institute of Organic Synthesis, Latvian Academy of Sciences, Riga, U.S.S.R.
authors.forename: B
authors.initials: B
authors.lastname: Vesterman
authors.forename: K
authors.initials: K
authors.lastname: Bobrowski
authors.forename: J
authors.initials: J
authors.lastname: Betins
authors.forename: G V
authors.initials: GV
authors.lastname: Nikiforovich
authors.forename: K L
authors.initials: KL
authors.lastname: Wierzchowski
mesh_terms: D004579:Electron Transport; D004744:Enkephalin, Methionine / Q000737:chemistry*; D005609:Free Radicals; D008715:Methionine / Q000737:chemistry*; D010084:Oxidation-Reduction; D011487:Protein Conformation; D014443:Tyrosine / Q000737:chemistry*
chemical_list: D005609:Free Radicals; D014443:Tyrosine; D004744:Enkephalin, Methionine; D008715:Methionine