@article{ref1,
title="Analysis of new growth promoting black market products",
journal="Growth hormone and IGF research",
year="2018",
author="Krug, Oliver and Thomas, Andreas and Malerød-Fjeld, Helle and Dehnes, Yvette and Laussmann, Tim and Feldmann, Ingo and Sickmann, Albert and Thevis, Mario",
volume="41",
number="",
pages="1-6",
abstract="Detecting agents allegedly or evidently promoting growth such as human growth hormone (GH) or growth hormone releasing peptides (GHRP) in doping controls has represented a pressing issue for sports drug testing laboratories. While GH is a recombinant protein with a molecular weight of 22 kDa, the GHRPs are short (3-6 amino acids long) peptides with GH releasing properties. The endogenously produced GH (22 kDa isoform) consists of 191 amino acids and has a monoisotopic molecular mass of 22,124 Da. Within this study, a slightly modified form of GH was discovered consisting of 192 amino acids carrying an additional alanine at the N-terminus, leading to a monoisotopic mass of 22,195 Da. This was confirmed by top-down and bottom-up experiments using liquid chromatography coupled to high resolution/high accuracy mass spectrometry. Additionally, three analogues of GHRPs were identified as Gly-GHRP-6, Gly-GHRP-2 and Gly-Ipamorelin, representing the corresponding GHRP extended by a N-terminal glycine residue. The structure of these peptides was characterised by means of high resolution (tandem) mass spectrometry, and for Gly-Ipamorelin and Gly-GHRP-2 their identity was additionally confirmed by custom synthesis. Further, established in-vitro experiments provided preliminary information considering the potential metabolism after administration.<br><br>Copyright © 2018. Published by Elsevier Ltd.<p /> <p>Language: en</p>",
language="en",
issn="1096-6374",
doi="10.1016/j.ghir.2018.05.001",
url="http://dx.doi.org/10.1016/j.ghir.2018.05.001"
}