D-Ser-containing humanin shows promotion of fibril formation.
Hayashi. Kanehiro K; Sasabe. Jumpei J; Chiba. Tomohiro T; Aiso. Sadakazu S; Utsunomiya-Tate. Naoko N
Key Findings
- Humanin can protect neurons from Alzheimer‑related damage.
- Replacing both serine residues with D‑serine increases humanin’s tendency to form fibrils.
- The increased fibril formation may enhance humanin’s neuroprotective activity.
Practical Outcomes
- For biohackers, the take‑away is that a D‑serine‑modified version of humanin could be more effective, but the evidence is still pre‑clinical. No dosage or safety data are available yet, so it’s not ready for self‑experimentation without further research.
Summary
Researchers found that swapping the normal L‑serine amino acids in the 24‑letter peptide humanin for their mirror‑image D‑serine versions makes the peptide clump together into fibrils more readily, and this clumping might boost its ability to protect brain cells. The study is early‑stage and done in test‑tube experiments, not in people.
Abstract
Humanin (HN), a peptide of 24 amino acid residues, suppresses the neuronal cell death that is induced by the gene products of Alzheimer's disease. HN contains two Ser residues at positions 7 and 14. Because the proportion of D-Ser isomerized from L-Ser in proteins appears to increase as cellular organs age, we explored the structural effects of the isomerization of each Ser residue in HN. By using a thioflavin-T assay to detect fibril formation, we found that an HN derivative that contained two isomerized D-Ser residues had a greater tendency to form fibrils than did wild-type HN or HNs containing single D-Ser residues. A previous report showed that HN containing two D-Ser residues exerts neuroprotective activity. Our data, therefore, suggest that the fibril formation by HN that contains two D-Ser residues may promote HN neuroprotective activity.
Study Information
pubmed
2011
2011-07-07T00:00:00.000Z
10.1007/s00726-011-0971-6
5
19