title: Overcoming biofluid protein complexity during targeted mass spectrometry detection and quantification of protein biomarkers by MRM cubed (MRM3).
abstract: Targeted mass spectrometry in the so-called multiple reaction monitoring mode (MRM) is certainly a promising way for the precise, accurate, and multiplexed measurement of proteins and their genetic or posttranslationally modified isoforms. MRM carried out on a low-resolution triple quadrupole instrument faces a lack of specificity when addressing the quantification of weakly concentrated proteins. In this case, extensive sample fractionation or immunoenrichment alleviates signal contamination by interferences, but in turn decreases assay performance and throughput. Recently, MRM(3) was introduced as an alternative to MRM to improve the limit of quantification of weakly concentrated protein biomarkers. In the present work, we compare MRM and MRM(3) modes for the detection of biomarkers in plasma and urine. Calibration curves drawn with MRM and MRM(3) showed a similar range of linearity (R(2) > 0.99 for both methods) with protein concentrations above 1 μg/mL in plasma and a few nanogram per milliliter in urine. In contrast, optimized MRM(3) methods improve the limits of quantification by a factor of 2 to 4 depending on the targeted peptide. This gain arises from the additional MS(3) fragmentation step, which significantly removes or decreases interfering signals within the targeted transition channels.
authors.affiliation: UMR 5280 CNRS Université de Lyon1, Institut des Sciences Analytiques, Université de Lyon, 5 Rue de la Doua, 69100, Villeurbanne, France.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Jeudy
authors.forename: Arnaud
authors.initials: A
authors.lastname: Salvador
authors.forename: Romain
authors.initials: R
authors.lastname: Simon
authors.forename: Aurore
authors.initials: A
authors.lastname: Jaffuel
authors.forename: Catherine
authors.initials: C
authors.lastname: Fonbonne
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Léonard
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Gautier
authors.forename: Olivier
authors.initials: O
authors.lastname: Pasquier
authors.forename: Jerome
authors.initials: J
authors.lastname: Lemoine
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood*; D001798:Blood Proteins / Q000737:chemistry*; D006801:Humans; D013058:Mass Spectrometry; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D015415:Biomarkers; D001798:Blood Proteins