A SAR Study of the Complete Ala and Partial Aib Scans of the Growth Hormone Releasing Factor: (Nle27hGRF(1-29)-NH2,

Abstract : In an attempt to determine which conformational parameters are important for biological expression of GRF activity, we and others have synthesized and biologically characterized rat or human GRF(1-29)-NH2) analogs with substitution of each amino acid by its corresponding D-isomer. Interestingly, the second structural analysis of hGRF(1-29)-NH2 indicated 90% alpha-helicity in 75% MeOH at pH 6 or 20% alpha-helicity in water at pH 3 with the helical portions being centrally located.