GHRP-6
Growth Hormone Releasing Peptide-6, Growth hormone-releasing hexapeptide, His-D-Trp-Ala-Trp-D-Phe-Lys-NH2
Structure-activity analysis of the growth hormone secretagogue GHRP-6 by alpha- and beta-amino gamma-lactam positional scanning.
Boutard. Nicolas N; Jamieson. Andrew G AG; Ong. Huy H; Lubell. William D WD
Key Findings
- Eleven new GHRP-6 analogs with alpha- or beta‑amino gamma‑lactam groups were synthesized.
- Binding affinity (IC50) to GHS‑R1a and CD36 receptors varied depending on the lactam type and its position, especially at Ala3 and D‑Phe5.
- Lactam substitution can be used to tune selectivity between the two receptors.
Practical Outcomes
- For the biohacker community, this work shows that tweaking GHRP-6’s structure can change which body receptors it targets, hinting at future more selective versions. However, the study does not provide new dosing guidelines or immediate performance benefits, so it’s mainly of scientific interest until such analogs become available for testing.
Summary
Researchers made new versions of the peptide GHRP-6 by swapping in small ring-shaped building blocks (lactams) at specific spots. They tested how well these new peptides stick to two receptors (the growth‑hormone secretagogue receptor and CD36) and found that changing the lactam at certain positions can shift the peptide’s preference for one receptor over the other.
Abstract
Incorporation of amino lactams into biologically active peptides restricts conformational mobility and may enhance selectivity and increase potency. alpha- and beta-amino gamma-lactams (Agl and Bgl), in both S and R configurations, were introduced into the growth hormone secretagogue GHRP-6 using a Fmoc-compatible solid-phase protocol relying on N-alkylation with five- and six-membered cyclic sulfamidates, followed by lactam annulation under microwave heating. Using this protocol in conjunction with IRORI Kan techniques furnished eleven new GHRP-6 analogs, and their binding affinity IC50 values on both the growth hormone secretagogue receptor 1a (GHS-R1a) and CD36 receptors are herein reported. The results indicate that selectivity towards one receptor or the other can be modulated by lactam substitution, typically at the Ala3 and the D-Phe5 positions.
Study Information
pubmed
2010
2010-01-01T00:00:00.000Z
10.1111/j.1747-0285.2009.00913.x
27
51