Conformational Effects on the Acidities of Small Peptides

摘要

N-terminal cysteine polyalanine peptides are much more acidic than the corresponding C-terminal ones. N-terminal cysteine polyglycine peptides are slightly more acidic than the corresponding C-terminal ones. Tripeptides are more acidic than the corresponding dipeptides. Deprotonated C-terminal cysteine polyalanine peptides adopt different conformations from those of the N-terminal analogues. All deprotonated polyglycine peptides exist in coils.