Search

Abstract: In order to describe developmental changes in human salivary peptidome, whole saliva was obtained from 98 infants followed longitudinally at 3 and 6months of age. Data on teeth eruption and diet at the age of 6months were also recorded. Salivary peptide extracts were characterised by label-free MALDI-MS. Peptides differentially expressed between the two ages, and those significantly affected by teeth eruption or introduction of solid foods were identified by MALDI TOF–TOF and LC ESI MS–MS. Out of 81 peaks retained for statistical analysis, 26 were overexpressed at the age of 6months. Exposure to solid foods had a more pronounced effect on profiles (overexpression of nine peaks) than teeth eruption (overexpression of one peak). Differential peaks corresponded to fragments of acidic and basic PRPs, statherin and histatin. Comparison with existing knowledge on adult saliva peptidome revealed that proteolytic processing of salivary proteins is qualitatively quite comparable in infants and in adults. However, age and diet are modulators of salivary peptidome in human infants. [Copyright &y& Elsevier]

The interindividual variation in the sensitivity to bitterness is attributed in part to genetic polymorphism at the taste receptor level, but other factors, such as saliva composition, might be involved. In order to investigate this, 2 groups of subjects (hyposensitive, hypersensitive) were selected from 29 healthy male volunteers based on their detection thresholds for caffeine, and their salivary proteome composition was compared. Abundance of 26 of the 255 spots detected on saliva electrophoretic patterns was significantly different between hypo- and hypersensitive subjects. Saliva of hypersensitive subjects contained higher levels of amylase fragments, immunoglobulins, and serum albumin and/or serum albumin fragments. It also contained lower levels of cystatin SN, an inhibitor of protease. The results suggest that proteolysis occurring within the oral cavity is an important perireceptor factor associated to the sensitivity to the bitter taste of caffeine. [ABSTRACT FROM AUTHOR]

Abstract: In order to document inter-individual variability in salivary protein patterns, unstimulated whole saliva was obtained from 12 subjects at 10 am and 3 pm of the same day. Saliva proteins were separated using two-dimensional gel electrophoresis, and semi-quantified using image analysis. One-way ANOVA was used to test the effects “time of sampling” and “subject”. Data were further explored by multivariate analyses (PCA, hierarchical clustering). Spots of interest were identified by mass spectrometry (MALDI-TOF MS/MS and nanoLC ESI-IT MS/MS). A dataset of 509 spots matched in all gels was obtained. There was no diurnal statistical effect on salivary patterns while inter-individual variability was high with 47 spots differentially expressed between subjects (p <1%). Clustering of these spots revealed that subjects could be discriminated first based on several proteins participating to the non-specific immune response (cystatins, lipocalin 1, parotid-secretory protein and prolactin-induced protein). Independently, subjects were also differentiated by their level of proteins originating from serum and involved in the immune system (complement C3, transferrin, IgG2), as well as the relative abundance of enzymes involved in carbohydrates metabolism (amylase and glycolytic enzymes). Inter-individual variability should be accounted for when searching for salivary biomarkers or when studying in-mouth biochemical mechanisms. [Copyright &y& Elsevier]