CONFORMATIONAL STABILITY OF A TYPE II' BETA-TURN MOTIF IN HUMAN GROWTH-HORMONE-[6-13] PEPTIDE ANALOGS AT HYDROPHOBIC SURFACES

The interactive properties of several peptides related to human growth hormone (hGH) [6-13] containing a type II' beta-turn motif have been investigated using reversed-phase high-performance liquid chromatograp hy (RP-HPLC). Various chromatographic parameters related to the hydrop hobic interactive surface area and binding affinity were measured over the range of temperatures between 5 and 85 degrees C. Variations in t hese parameters were consistent with significant differences in the re lative stability of the type II' beta-turn structures of these peptido mimetics. The effect of changes in peptide conformation were also inve stigated through the analysis of band-broadening behaviour during the chromatographic process. Significant variations in bandwidth observed at discrete temperatures were related to the rate of interconversion b etween the type II' beta-turn and more extended conformers. These inve stigations further document the potential of RP HPLC for monitoring su btle changes in peptide secondary structure at hydrophobic interfaces. (C) Munksgaard 1997.