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Solution three‐dimensional structure of surfactin: A cyclic lipopeptide studied by 1 H‐nmr, distance geometry, and molecular dynamics
Author(s) -
Bonmatin JeanMarc,
Genest Monique,
Labbé Henri,
Ptak Marius
Publication year - 1994
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.360340716
Subject(s) - chemistry , surfactin , molecular dynamics , polar , ring (chemistry) , crystallography , molecular model , lipopeptide , stereochemistry , chemical physics , computational chemistry , bacillus subtilis , organic chemistry , physics , genetics , astronomy , bacteria , biology
Abstract The solution three‐dimensional structure of the protonated [Leu7]‐surfactin, an hepta‐peptide extracted from Bacillus subtilis , has been determined from two‐dimensional 1 Hnmr performed in 2 H 6 ‐dimethylsulfoxide and combined with molecular modeling. Experimental data included 9 coupling constants, 61 nuclear Overhauser effect derived distances, NH temperature coefficients, and 13 C relaxation times. Two distance geometry (DISMAN) protocols converged toward models of the structure and the best of them were refined by restrained and unrestrained molecular dynamics (GROMOS). Two structures in accord with the set of experimental constraints are presented. Both are characterized by a “horse saddle” topology for ring atoms on which are attached the two polar Glu and Asp side chains showing an orientation clearly opposite to that of the C 11–13 aliphatic chain. Amphipathic and surface properties of surfactin are certainly related to the existence of such minor polar and a major hydrophobic domains. The particular “claw” configuration of acidic residues observed in surfactin gives important clues for the understanding of its cation binding and transporting ability. © 1994 John Wiley & Sons, Inc.