Conformation and hydrogen bonding of N-formylmethionyl peptides. II. Crystal and molecular structure of N-formyl-L-methionyl-L-phenylalanine.
Crystals of N-formyl-L-methionyl-L-phenylalanine (C15H20N2O4S), grown from aqueous methanol solution are orthorhombic, space group, P2(1)2(1)2(1), with cell parameters at 294K of a = 4.900(2), b = 17.947(4), c = 18.726(4)A, V = 1646.8A3, M.W. = 324.4, Z = 4 and Dm = 1.308 g/cc, and as expected, all nearly identical to that of N-f-D-Met-D-Phe studied by Jeffs, Heald, Chodosh & Eggleston (Int. J. Peptide Protein Res. 24, 442-446, 1984). The crystal structure was solved and refined using CAD-4 data (1095 reflections greater than or equal to 3 sigma) to a final R value of 0.042. Molecules related by the alpha-translation form a parallel beta-sheet rather than anti-parallel sheet as stated in the earlier study of Jeffs et al. The formation of the parallel rather than the anti-parallel beta-sheet structure, the use of the C-H ...O hydrogen bonds to stabilize the beta-sheet and the very short O-H ...O hydrogen bond between the carboxyl OH and the N-acyl oxygen atom emerge as the main structural features of the chemotactic N-formyl methionyl peptides.
Parthasarathy
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Center for Crystallographic Research, Roswell Park Memorial Institute, Buffalo, New York.
Fridey
S M
SM
Srikrishnan
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D002630:Chemotactic Factors; D003460:Crystallization; D004151:Dipeptides; D006860:Hydrogen Bonding; D008715:Methionine / Q000031:analogs & derivatives; D008958:Models, Molecular; D009239:N-Formylmethionine; D011487:Protein Conformation
D002630:Chemotactic Factors; D004151:Dipeptides; C017330:N-formylmethionylphenylalanine; D009239:N-Formylmethionine; D008715:Methionine