GHRP-6
Growth Hormone Releasing Peptide-6, Growth hormone-releasing hexapeptide, His-D-Trp-Ala-Trp-D-Phe-Lys-NH2
Interaction between a growth-hormone releasing hexapeptide and phospholipids spread as monolayers at the air/water interface.
Issaurat. B B; Teissié. J J
Key Findings
- GHRP‑6 contains two tryptophan residues that make it fluoresce, allowing researchers to track it in the membrane model.
- When mixed with phosphatidylethanolamine, the peptide‑lipid complex breaks apart under compression.
- With phosphatidylglycerol, the complex remains intact, though its fluorescence drops reversibly at high surface pressure.
- Hydrophobic forces between GHRP‑6 and lipids are weak, but electrostatic forces can hold the peptide to the membrane without damaging the lipid layer.
Practical Outcomes
- The study suggests that GHRP‑6 can be formulated with certain lipid carriers (like phosphatidylglycerol) without harming cell‑like membranes, which is useful for creating stable oral or injectable preparations. However, the choice of lipid matters, as some (e.g., phosphatidylethanolamine) may cause the peptide to detach under stress. This information helps biohackers design safer, more reliable delivery systems for GHRP‑6.
Summary
Scientists looked at how the growth‑hormone‑releasing peptide GHRP‑6 sticks to thin layers of fat‑like molecules (phospholipids). They found that the peptide can bind to these layers without breaking them, but the strength of the bond depends on the type of phospholipid. In some lipids the bond falls apart when the layer is squeezed, while in others it stays together but changes its glow (fluorescence) in a reversible way.
Abstract
The interaction between a growth-hormone releasing hexapeptide and phospholipids was studied on mixed monolayers models by means of surface fluorescence. When in a monolayer this hexapeptide which contains two tryptophan molecules was observed to fluoresce. Isothermal compression experiments showed that the complex was destroyed upon compression in the case of phosphatidylethanolamine. With phosphatidylglycerol it was observed to be stable but a dramatic reversible decrease in emission was observed at high surface pressure. This is indicative of a reversible change in the organization of the peptide-phospholipid complex. These observations indicate that, in the complex, hydrophobic interactions were weak but electrostatic ones, when present, were strong enough to maintain the GHRP attached to the monolayer and not to destabilize it. The integrity of the lipid monolayer appeared not to be affected by the peptide.
Study Information
pubmed
1988
1988-10-20T00:00:00.000Z
10.1016/0005-2736(88)90523-8
3
9