[Proteolysis of semax analogues with different N-t... - Semax Study

Key Findings

Changing the N‑terminal Met to Ala, Gly, or Thr makes semax more resistant to aminopeptidase degradation.

The Trp‑substituted analogue breaks down into two major fragments (Sem‑5 and Sem‑6) in roughly equal amounts.

All tested analogues act as inhibitors of semax proteolysis, potentially extending semax’s activity.

Practical Outcomes

For biohackers using semax for cognition or neuro‑protection, choosing analogues with Ala, Gly, or Thr at the first position could provide a longer‑lasting effect, possibly allowing lower or less frequent dosing. The Trp version may have a different metabolic profile, which could be useful for tailoring effects. However, human safety and efficacy data are still needed before swapping out the standard peptide.

Summary

Researchers tested how swapping the first amino acid in the brain‑active peptide semax changes how quickly it gets broken down by enzymes. Replacing the natural methionine with alanine, glycine, or threonine makes the peptide last longer, while a tryptophan swap leads to a mix of breakdown products. All the variants can also slow down the breakdown of regular semax.

Abstract

Proteolysis of semax (Met-Glu-His-Phe-Pro-Gly-Pro, Sem) and its analogues ([Ala1]Sem, [Gly1]Sem, [Thr1]Sem, [Trp1]Sem) that are differ from semax in substitution of N-terminal Met residue were studied. It is shown that such replacement changes the rate of peptides degradation by N-aminopeptidases (EC 3.4.11.2, Sigma, Type VI, 9.2 units. Akt. / mg). [Ala1]Sem, [Gly1]Sem and [Thr1]Sem semax analogues proved to be more stable to proteolysis than semax (Sem), and their initial product of proteolysis is His-Phe-Pro-Gly-Pro (Sem-5). For triptophan analogue both Glu-His-Phe-Pro-Gly-Pro (Sem-6) and Sem-5 product are formed in similar quantities. It is found that all investigated analogues can be used as inhibitors in Sem proteolysis.

Study Information

Provider

pubmed

Year

2011

DOI

10.1134/s1068162011040133