Figure 1.
Classification of subjects by PROP taster status.
All values are means (± SEM). Three-way ANOVA was used to compare PROP intensity ratings with NaCl intensity ratings in PROP super-tasters (n = 24) and nontasters (n = 21) (p<0.001). * indicates significant difference between PROP and the corresponding NaCl concentration (p<0.001; Newman-Keuls test). Medium tasters were not studied.
Figure 2.
Examples of HPLC-MS profiles from un-stimulated saliva and extracted ion current peaks.
(A) HPLC-MS Total Ion Current (TIC) profiles of the acidic-soluble fraction of saliva of a representative PROP super-taster (white profile) and nontaster (grey profile). (B) The ion current (XIC) peaks of Ps-1 protein and II-2 peptide extracted from the HPLC-MS profiles of the same subjects. The XIC peaks of the PROP super-taster (white filled) are superimposed on the same XIC peaks of the nontaster (grey filled).
Figure 3.
Relationships between PROP taste responsiveness and the basal level of salivary proteome.
Mean values ± SEM of the XIC peak areas of the six protein families (P-B, bPRP, aPRP, S-Cyst, Stath, Hist) (upper graph), and of the following individual bPRPs (P-F, P-J, P-D, P-H, IB-8a Tot, II-2 Tot, IB-1 Tot, 10434 and Ps-1) (lower graph) in PROP super-taster (n = 24) and nontaster (n = 21) un-stimulated saliva. * = significant difference between PROP super-tasters and nontasters (p<0.001; Newman-Keuls test subsequent to two-way ANOVA).
Figure 4.
Relationships between PROP taste responsiveness and the salivary proteome after PROP bitter taste stimulation.
Mean values ± SEM of the XIC peak areas of the six protein families (P-B, bPRP, aPRP, S-Cyst, Stath, Hist) (upper graph), and of the following individual bPRPs (P-F, P-J, P-D, P-H, IB-8a Tot, II-2 Tot, 10434 and Ps-1) in PROP super-taster (n = 24) and nontaster (n = 21) saliva before (0 in the X-axis) and after PROP (3.2 mM) stimulation. (The numbers 1, 2, 3 on the X-axis correspond to immediately after stimulation, after 5 and 10 min from stimulation, respectively). Different letters indicate significant difference (p≤0.025; Newman-Keuls test subsequent to three-way ANOVA).
Table 1.
List of salivary proteins and peptides quantified by RP-HPLC-ESI-MS.