Action of serine carboxypeptidase from paecilomyces carneus on oligopeptides containing carboxy-terminally amidated peptides.
Umetsu. H H; Hishinuma. K K; Wake. H H; Takeuchi. M M; Ichishima. E E
Key Findings
- The enzyme removes amino acids one by one from the carboxy‑terminus of neurotensin, angiotensin I, bradykinin, and delta‑sleep‑inducing peptide.
- Its activity is slowed when the peptide has a Gly‑X, Pro‑X, X‑Gly, or X‑Pro pattern near the cleavage site.
- Bulky residues (Arg, Met, Leu, Phe) in the penultimate positions shift the enzyme from a carboxyamidase to an amidase mode, and the third‑from‑end residue also influences this behavior.
Practical Outcomes
- For most DIY health enthusiasts, this research doesn’t change how you take or dose peptide supplements. It may be useful for people formulating peptide drugs, as it highlights how certain enzyme activities could degrade amidated peptides, suggesting the need for protective formulations.
Summary
Scientists studied a fungal enzyme that chops off amino acids from the end of several brain‑related peptides. The enzyme works differently depending on the type of amino acids near the end of the peptide, especially if they are bulky or proline‑containing.
Abstract
Paecilomyces carneus carboxypeptidase sequentially liberated amino acids from the carboxy-terminus of neurotensin, angiotensin I, bradykinin, and delta sleep-inducing peptide, indicating that the sequential hydrolysis of peptides was limited by the occurrence of intermediates with the structure of -Gly-X (X = L-amino acid), -Pro-X, -X-Gly, and -X-Pro. The enzyme had carboxyamidase and/or amidase activities for the carboxy-terminally amidated peptides. The enzyme essentially acted as a carboxyamidase for the long carboxy-terminally amidated peptides; an amidase became dominant for the substrates in the presence of bulky amino acids such as Arg, Met, Leu, and Phe in the penultimate (P1) and P2 positions, corresponding with the S1 and S2 sites of the enzyme, and the P3 position of carboxy-terminally amidated peptides played a significant role in the action as a carboxyamidase or a amidase.
Study Information
pubmed
1998
10.1007/s002849900277
16