Time-dependent changes in the early salivary proteome after oral stimulation with wine differs by the individual 6--propylthiouracil (prop) taster status.

Differences in the oral responsiveness to the bitter compound 6--propylthiouracil (PROP) between taster (T) and non-taster (NT) individuals have also been related to differences in the long-lasting wine astringency perception, which could be linked to differences in the dynamics of the salivary protein profile upon wine stimulation, depending on the individual PROP taste status (PTS). To check this, the time-course changes in the early protein salivary profile (30 and 60 seconds) after the oral stimulation with a red wine (CRW) and with the same tannin-enriched wine (TRW) in Ts and NTs (young women) were tested by using an untargeted proteomic approach. Results showed that Ts exhibited more pronounced protein changes (measured as the ratio of protein abundance before and after wine stimulation), compared to NTs, including proteins such as cystatins (SN, S, SA and D), α-amylase, prolactin (PIP), carbonic anhydrase VI (CA-VI) and acid proline-rich proteins (aPRP).

Multi-laboratory experiment PME11 for the standardization of phosphoproteome analysis.

Global analysis of protein phosphorylation by mass spectrometry proteomic techniques has emerged in the last decades as a powerful tool in biological and biomedical research. However, there are several factors that make the global study of the phosphoproteome more challenging than measuring non-modified proteins. The low stoichiometry of the phosphorylated species and the need to retrieve residue specific information require particular attention on sample preparation, data acquisition and processing to ensure reproducibility, qualitative and quantitative robustness and ample phosphoproteome coverage in phosphoproteomic workflows.

A multicentric study to evaluate the use of relative retention times in targeted proteomics.

Unlabelled: Despite the maturity reached by targeted proteomic strategies, reliable and standardized protocols are urgently needed to enhance reproducibility among different laboratories and analytical platforms, facilitating a more widespread use in biomedical research. To achieve this goal, the use of dimensionless relative retention times (iRT), defined on the basis of peptide standard retention times (RT), has lately emerged as a powerful tool. The robustness, reproducibility and utility of this strategy were examined for the first time in a multicentric setting, involving 28 laboratories that included 24 of the Spanish network of proteomics laboratories (ProteoRed-ISCIII).