Arg side-chain-backbone interactions evidenced in model peptides by 17O-NMR spectroscopy.
The guanidinium group of arginine possesses a variety of biochemical functions, either by participating in direct interactions in recognition processes, or by stabilizing secondary structures. Three model compounds, selectively (17)O enriched, Ac-Arg-Ala-[(17)O]Pro-NH(2) (1), Piv-Arg-Pro-[(17)O]Gly-NH(2) (2) (C-terminal segment of the luteinizing hormone releasing hormone), and Piv-Nle-Pro-[(17)O]Gly-NH(2) (3), were prepared and studied by (17)O-nmr spectroscopy. A direct hydrogen-bonded interaction between the Arg side chain and the carbonyl main chain carboxy-terminus was found, thus confirming the tendency of Arg to participate in proton-acceptor functions.
Tsikaris
V
V
Department of Chemistry, Section of Organic Chemistry and Biochemistry, University of Ioannina, 451 10 Ioannina, Greece. btsikari@cc.uoi.gr
Troganis
A
A
Moussis
V
V
Panou-Pomonis
E
E
Sakarellos-Daitsiotis
M
M
Sakarellos
C
C
D001120:Arginine / Q000737:chemistry*; D007987:Gonadotropin-Releasing Hormone / Q000737:chemistry; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D009842:Oligopeptides / Q000737:chemistry*; D010103:Oxygen Isotopes; D010446:Peptide Fragments / Q000737:chemistry
D009842:Oligopeptides; D010103:Oxygen Isotopes; D010446:Peptide Fragments; D007987:Gonadotropin-Releasing Hormone; D001120:Arginine