Send to

Choose Destination
Biochemistry. 2004 Jun 29;43(25):8021-8.

Synthetic cross-links arrest the C-terminal region of the relaxin-like factor in an active conformation.

Author information

Department of Biochemistry and Molecular Biology, Medical University of South Carolina, 173 Ashley Avenue, P.O. Box 250509, Charleston, South Carolina 29425, USA.


All kinetic indicators suggest that the receptor-binding site of the relaxin-like factor (RLF) is located in the flexible C-terminal region of the B chain and is centered about the tryptophan in position B27. Conformational restraints of varying lengths were used to confine Trp (B27) to a narrow range of positions relative to the C terminus of the A chain. Total synthesis of variants involving residues proximate to Trp (B27) assured us that none had a role in receptor binding. Even arginine B26, next to the important tryptophan, can be replaced without deleterious effects. To fix the distance between the C-terminal end of the A chain and Trp (B27) at predetermined lengths, we synthesized RLF with covalent cross-links between a lysine, which was placed in position B26, and the alpha-carboxyl group at the C terminus of the A chain (A26). The affinity of the cross-linked ligands for the RLF receptor varied as a parabolic function of length whereby the range of 10.0-11.1 A provided the closest approach to the binding conformation. Wild-type transmembrane signaling activity, as determined by cAMP accumulation, was reached only with a glycine cross-linker.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for American Chemical Society
Loading ...
Support Center