Synthesis of Mono-PEGylated Growth Hormone Releasing Peptide-2 and Investigation of its Biological Activity.
Hu. Xiaoyu X; Xu. Beihua B; Zhou. Ziniu Z
Key Findings
- Mono‑PEGylated GHRP‑2 can be efficiently synthesized using mPEG‑NHS ester in DMF or DMSO.
- In rats, the PEG‑linked GHRP‑2 has a longer plasma half‑life and more stable activity than the unmodified peptide.
- The PEG modification does not significantly reduce the peptide’s biological activity.
Practical Outcomes
- If PEGylated GHRP‑2 can be made for human use, it could mean fewer injections and more sustained effects, which is attractive for longevity or performance protocols. However, the data are from animal studies only, so real‑world dosing, safety, and efficacy in people remain unknown. Enthusiasts should wait for human trials before changing their GHRP‑2 routines.
Summary
Researchers made a version of the growth‑hormone‑releasing peptide GHRP‑2 that’s attached to a small PEG molecule, and they showed in rats that this PEG‑linked peptide stays active longer in the blood without losing much of its effect. The study is pre‑clinical, so it hints at a way to make GHRP‑2 work for a longer time, but it doesn’t give direct dosing advice for people yet.
Abstract
The purpose of this study was to investigate an efficient synthetic route to the mono-PEGylated growth hormone releasing peptide-2 (GHRP-2) and its biological activity in vivo. The commercially available key PEGylating reagent, mPEG-NHS ester, was successfully utilized to the synthesis of mono-PEGylated GHRP-2, during which the PEGylation profiles of GHRP-2 were monitored by high-performance liquid chromatography (HPLC). The product was purified by cation exchange chromatography, and its biological activity was conducted in rats. The desired mono-PEGylated GHRP-2 as the major product was readily obtained in anhydrous aprotic solvent, such as dimethyl formamide (DMF) and dimethylsulfoxide (DMSO), when the molar ratio of mPEG-NHS ester to GHRP-2 was fixed to be 0.8:1. The products were characterized by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry. The evaluation of the biological activity for the products showed that the mono-PEGylated GHRP-2 gave a more stable activity than GHRP-2, suggesting that PEGylation led to the increase in the half-life of GHRP-2 in plasma without greatly impairing the biological activity. PEGylation of the GHRP-2 is a good choice for the development of the GHRP-2 applications.
Study Information
pubmed
2015
2015-03-12T00:00:00.000Z
10.1208/s12249-015-0307-z
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