Hydrolytic Cleavage of Pyroglutamyl-Peptide Bond. I. The Susceptibility of Pyroglutamyl-Peptide Bond to Dilute Hydrochloric Acid

概要

論文の詳細を見る
The susceptibility of the pyroglutamyl-peptide bond in some biologically active peptides, dog neuromedin U-8 fragment (pGlu-Phe-Leu-Phe-Arg-Pro-Arg-OH), human big gastrin fragment (pGlu-Leu-Gly-Pro-OH) and thyrotropin releasing hormone (TRH) fragments (pGlu-His-Pro-OH, pGlu-His-OH), to 1N HCl under mild conditions and/or at 60℃ was studied. It was found that the N-terminal portion of pGlu-peptides is extremely labile to acid hydrolysis, giving not only the ring-opened product of the pyrrolidone of the pGlu residue, but also the cleavage product of the pGlu-peptide linkage. The ring-opening reaction predominated over the cleavage reaction in hydrolysis of the four peptides in 1N HCl at 60℃. The ring-opening reaction and the cleavage reaction of pGlu-peptide linkage proceeded faster than the cleavage of internal peptide bonds. The rate of hydrolysis was affected by the reaction temperature, and the ring-opening reaction was greatly diminished at 4℃ in comparison with the cleavage reaction. Thus, the phenomenon that the pGlu-peptide bond is susceptible to dilute HCl as compared to the other peptide bonds appears to be a general one.
社団法人日本薬学会の論文
1995-12-15