A cyclodecapeptide ligand to vitamin B12.
Libraries of cyclic decapeptides were screened with vitamin B(12) derivatives to give cyclic peptide ligands incorporating histidine and cysteine as coordinating residues and negatively charged amino acids. Two hits, cyclo-(HisAspGluProGlyIleAlaThrProdGln) and cyclo-(ValAspGluProGlyGluAspCysProdGln) were resynthesized in good yields for solution experiments. The peptides bind aquocobalamin with coordination of His or Cys to the cobalt with high affinities (K(a) approximately 10(5) M(-1)). Additional interactions between the peptide side chains and the vitamin B(12) corrin moiety were determined by studying the (1)H NMR solution structure. The cyclopeptide-cobalamin complex with the histidine residue showed enhanced stability towards cyanide exchange, demonstrating the shielding effect of the ligand on the metal center.
Duléry
Vincent
V
Département de Chimie Moléculaire-UMR-CNRS 5250 & ICMG FR 2607, Université Joseph Fourier, BP 51, 38041, Grenoble Cedex 9, France.
Uhlich
Nicolas A
NA
Maillard
Noélie
N
Fluxá
Viviana S
VS
Garcia
Julian
J
Dumy
Pascal
P
Renaudet
Olivier
O
Reymond
Jean-Louis
JL
Darbre
Tamis
T
D000595:Amino Acid Sequence; D003486:Cyanides / Q000378:metabolism; D015195:Drug Design; D007700:Kinetics; D008024:Ligands; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism*; D010456:Peptides, Cyclic / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D014805:Vitamin B 12 / Q000378:metabolism*
D003486:Cyanides; D008024:Ligands; D009842:Oligopeptides; D010456:Peptides, Cyclic; D014805:Vitamin B 12