5776
BIOCHEMISTRY
CANN,
CHANNABASAVAIAH,
AND STEWART
Circular Dichroism Study of the Solution Conformation of Luteinizing Hormone Releasing Hormone? John R. C a m , * K. Channabasavaiah, and John M. Stewart
ABSTRACT: A systematic investigation has been made into the circular dichroic behavior of luteinizing hormone releasing hormone and its peptide fragments and deletion analogues. The results are interpreted to mean that the hormone exists in solution as an ensemble of conformers with different sensitivities to temperature and solvent composition. The farultraviolet circular dichroic spectra exhibited by the hormone
under different experimental conditions can be simulated satisfactorily by the weighted addition of the spectra of its aliphatic- and aromatic-containing halves. However, the structure of the hormone is not simply the sum of its halves, since some conformational feature of the intact molecule perturbs the near-ultraviolet circular dichroism of its aromatic residues.
L u t e i n i z i n g hormone releasing hormone (LHRH)' is a decapeptide with the amino acid sequence