title: Quantification of matrix metalloprotease-9 in bronchoalveolar lavage fluid by selected reaction monitoring with microfluidics nano-liquid-chromatography-mass spectrometry.
abstract: Quantitative protein analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in the selected reaction monitoring (SRM) mode was used to quantify matrix metalloprotease-9 (MMP-9; ∼90 kDa) in bronchoalveolar lavage fluid (BALF) from patients having undergone lung transplantation. We developed an SRM assay for microfluidics-based nanoLC-MS/MS on a triple quadrupole mass spectrometer based on two signature peptides. Samples were prepared by chloroform-methanol precipitation followed by trypsin digestion in the presence of stable-isotope-labeled internal peptide standards. The method allows accurate quantification of MMP-9 in BALF with an LLOQ of 2.9 ng/mL and an LLOD of 0.25 ng/mL without the use of extensive fractionation or antibodies.
authors.affiliation: Analytical Biochemistry, Department of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands.
authors.forename: Laurette M
authors.initials: LM
authors.lastname: Prely
authors.forename: Krisztina
authors.initials: K
authors.lastname: Paal
authors.forename: Jos
authors.initials: J
authors.lastname: Hermans
authors.forename: Sicco
authors.initials: S
authors.lastname: van der Heide
authors.forename: Antoon J M
authors.initials: AJ
authors.lastname: van Oosterhout
authors.forename: Rainer
authors.initials: R
authors.lastname: Bischoff
mesh_terms: D000595:Amino Acid Sequence; D015415:Biomarkers / Q000032:analysis; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry*; D002725:Chloroform / Q000737:chemistry; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D016014:Linear Models; D016040:Lung Transplantation; D020780:Matrix Metalloproteinase 9 / Q000032:analysis*; D000432:Methanol / Q000737:chemistry; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000032:analysis; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014357:Trypsin / Q000737:chemistry
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; D002725:Chloroform; D014357:Trypsin; D020780:Matrix Metalloproteinase 9; D000432:Methanol