Carboxypeptidase mediated C-terminal amidation of polypeptide acids.
Aasmul-Olsen. S S; Christensen. K A KA; Widmer. F F
Key Findings
- Carboxypeptidase‑mediated transpeptidation can efficiently amidate C‑terminal peptide acids.
- Larger hydrophilic leaving groups (e.g., threonine) improve yields when arginine amide is the nucleophile for GRF‑1‑29 models.
- Recombinant secreted carboxypeptidase enables high yields even for longer peptides such as calcitonin variants.
Practical Outcomes
- For DIY peptide makers, the study suggests that using carboxypeptidase with appropriate leaving groups can be a viable route to produce amidated GRF‑1‑29 and similar peptides. However, the approach requires enzyme handling and may be more suited to well‑equipped labs rather than simple at‑home setups.
Summary
Scientists showed that a special enzyme called carboxypeptidase can turn peptide acids into the more stable peptide amides that we usually want, like the active form of GRF‑1‑29. By using bigger, water‑loving side‑chains (like threonine) as the leaving group, they got better yields, and the method works even for longer peptides when the enzyme is made in a recombinant form.
Abstract
The possibilities of obtaining polypeptide amides in good yields from polypeptide acids by carboxypeptidase catalyzed transpeptidation have been investigated in different C-terminal amidations catalysed by CPD-Y, placing particular emphasis on the structure of the leaving group. In models for GRF(1-29) acid, larger hydrophilic leaving groups like threonine were particularly useful in reactions with arginine amide acting as nucleophile. In models for calcitonin acids, good results were obtained using also large hydrophobics like methionine and tryptophane in amidations with ammonia acting as nucleophile. Influences on both rate and synthetic efficiency of similar trend, but different magnitude, were observed in both salmon and human calcitonin models and high yields were attainable also in longer peptides or if recombinant secreted enzyme was employed.
Study Information
pubmed
1991