Self-association and solubility of peptides. A solvent titration study of the 28-31 segment of corticotropin releasing factor.
Self-association of peptides related to the 28-31 sequence of corticotropin releasing factor in methylene chloride was disrupted by adding a variety of polar organic solvents in increasing amounts. This structural transition was monitored by the disappearance of either the amide-1 C = O stretching band (1635 cm-1) or the amide-A N-H stretching band (3300 cm-1) of strongly intermolecularly H-bonded molecules in the infrared absorption spectra. The effects induced by main-chain length, protection of the C-terminal group, nature of solvent, and peptide concentration were assessed. The increasing propensity to aggregate displayed by these peptides is paralleled by a decrease in their solubility.
D055598:Chemical Phenomena; D002621:Chemistry; D003346:Corticotropin-Releasing Hormone / Q000032:analysis*; D012995:Solubility; D012997:Solvents; D013055:Spectrophotometry, Infrared
D012997:Solvents; D003346:Corticotropin-Releasing Hormone