title: High sensitivity mass spectrometric quantification of serum growth hormone by amphiphilic peptide conjugation.
abstract: Amphiphilic peptide conjugation affords a significant increase in sensitivity with protein quantification by electrospray-ionization mass spectrometry. This has been demonstrated for human growth hormone (GH) in serum using N-(3-iodopropyl)-N,N,N-dimethyloctylammonium iodide as derivatizing reagent. The signal enhancement achieved is up to a factor of 5-6 and enables extension of the applicable concentration range down to the very low concentrations (≤ 1.0 µg/L) as encountered with clinical glucose suppression tests for patients with acromegaly. The method has been validated using a set of serum samples spiked with known amounts of recombinant 22 kDa GH in the range of 0.48 to 7.65 µg/L. The coefficient of variation (CV) calculated based on the deviation of results from the expected concentrations was 3.5%. The limit of detection (LoD) was determined as 0.1 µg/L and the limit of quantification (LoQ) as 0.4 µg/L. The potential of the method as a tool in clinical practice has been demonstrated with patient samples of about 1 µg/L.
authors.affiliation: Physikalisch-Technische Bundesanstalt, D-38116, Braunschweig, Germany. christian.arsene@ptb.de
authors.forename: Cristian G
authors.initials: CG
authors.lastname: Arsene
authors.forename: Dirk
authors.initials: D
authors.lastname: Schulze
authors.forename: Jürgen
authors.initials: J
authors.lastname: Kratzsch
authors.forename: André
authors.initials: A
authors.lastname: Henrion
mesh_terms: D002853:Chromatography, Liquid; D019382:Human Growth Hormone / Q000097:blood*; D006801:Humans; D040901:Proteomics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D019382:Human Growth Hormone