title: Improvement of the performance of targeted LC-MS assays through enrichment of histidine-containing peptides.
abstract: Mass spectrometric-based quantification using targeted methods has matured during the past decade and is now commonly used in proteomics. However, the reliability of protein quantification in complex matrixes using selected reaction monitoring is often impaired by interfering signals arising from coelution of nontargeted components. Sample preparation methods resulting in the reduction of the number of peptides present in the mixture minimizes this effect. One solution consists in the selective capture of peptides containing infrequent amino acids. The enrichment of histidine-containing peptides via immobilized metal-ion affinity chromatography loaded with Cu(2+) ions (IMAC-Cu) was applied in a quantitative workflow and found to be a simple and cost effective method for the reduction of sample complexity with high recovery and selectivity. When applied to a series of depleted human plasma digests, the method decreased nonspecific signals, resulting in a more precise and robust protein quantification. The method was also shown to be an alternative to HSA/IgG depletion during plasma protein analysis. This method, used in conjunction with recent improvements in the instrument's peak capacity, addresses a bottleneck generally encountered in quantitative proteomics studies by providing the robustness and throughput required for the analysis of large sample series without compromising the number of proteins monitored.
authors.affiliation: Luxembourg Clinical Proteomics Center, Centre de Recherche Public de la Santé (CRP-Santé) , Strassen 1445, Luxembourg.
authors.forename: Cédric
authors.initials: C
authors.lastname: Mesmin
authors.forename: Bruno
authors.initials: B
authors.lastname: Domon
mesh_terms: D000595:Amino Acid Sequence; D001798:Blood Proteins / Q000032:analysis / Q000378:metabolism; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods*; D006639:Histidine / Q000378:metabolism*; D006801:Humans; D007501:Iron / Q000378:metabolism; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D008969:Molecular Sequence Data; D010455:Peptides / Q000378:metabolism*; D020543:Proteome / Q000032:analysis / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D015203:Reproducibility of Results
chemical_list: D001798:Blood Proteins; D010455:Peptides; D020543:Proteome; D006639:Histidine; D007501:Iron
keywords: IMAC; Mass spectrometry; depletion; enrichment; histidine; selectivity; targeted proteomics