I3C N M R O F L H - R H
Conformational Flexibility of Luteinizing HormoneReleasing Hormone in Aqueous Solution. A Carbon- 13 Spin-Lattice Relaxation Time Study? Roxanne Deslauriers,* George C. Levy, W. Herbert McGregor, Dimitrios Sarantakis, and Ian C. P. Smith
ABSTRACT: The carbon-13 nuclear magnetic resonance
(I3C N M R ) spectra of luteinizing hormone-releasing hormone (LH-RH) and lower homologous peptides have been assigned in aqueous solutions at various p H values. I3C spin-lattice relaxation times ( T I )have been measured for all proton-bearing carbons at 25.2 and 67.9 MHz. From the
T h e structural characteristics of the hypothalamic factor which causes the release of luteinizing hormone and folliclestimulating hormone from the anterior pituitary have recently been elucidated (Burgus et al., 1972; Matsuo et al., 1971; Schally et al., 1972). Luteinizing hormone-releasing hormone (LH-RH)] stimulates the release of both luteinizing hormone and follicle-stimulating hormone (Kastin et a]., 1969, 1971). LH-RH is a polypeptide of sequence
