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A method for confirming CJC‐1295 abuse in equine plasma samples by LC–MS/MS
Author(s) -
Timms Mark,
Ganio Katherine,
Steel Rohan
Publication year - 2019
Publication title -
drug testing and analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.065
H-Index - 54
eISSN - 1942-7611
pISSN - 1942-7603
DOI - 10.1002/dta.2599
Subject(s) - chemistry , peptide , growth hormone , mass spectrometry , chromatography , blood proteins , blood plasma , biochemistry , hormone
Abstract CJC‐1295 is a peptide‐based drug that stimulates the production of growth hormone (GH) from the pituitary gland. It incorporates a functional maleimido group at the C‐terminus that allows it to covalently bind plasma proteins such as serum albumin. These CJC‐1295‐protein conjugates have a much greater half‐life compared to the unconjugated peptide and are capable of stimulating GH production for more than six days in humans after a single administration. Conjugated CJC‐1295 is difficult to detect in blood by mass spectrometry due to its low abundance, high molecular weight, and conjugation to a range of different protein substrates. Previously we described a screening procedure for the detection of CJC‐1295 in equine plasma using an immuno‐PCR assay. Here we demonstrate the confirmation of CJC‐1295 in equine plasma by LC−MS/MS after immuno‐affinity capture and tryptic digestion. Using this method, CJC‐1295 was identified down to concentrations as low as 180 pg/mL in 1 mL of equine plasma.