Results Skin prick test to mace and ginger (10%) were positive and specific IgE to Pru p3 and mace were detected. Double-blind, placebocontrolled, oral food challenge (DBPCFC) with this spice showed rhinitis in few minutes and was negative to ginger. Through electrophoresis of peach, Pru p3, mace and ginger extracts were identified and the corresponding proteins purified and characterized as al...

Thaumatin, a sweet-tasting plant protein, elicits a sweet taste sensation at 50 nM in humans but not rodents. Although it was shown that the cysteine-rich domain (CRD) of human T1R3 (hT1R3) is important for the response to thaumatin, the amino acid residues within CRD critical for response are still unknown. A comparison of the amino acid sequence (69 amino acid residues) of CRD between hT1R3 a...

Chitinases and thaumatin-like proteins are important grape proteins as they have a great influence on wine quality. The quantification of these proteins in grape juices and wines, along with their purification, is therefore crucial to study their intrinsic characteristics and the exact role they play in wines. The main isoforms of these two proteins from Chardonnay grape juice were thus purifie...

Thaumatin is an intensely sweet-tasting protein that elicits sweet taste at a concentration of 50 nM, a value 100,000 times larger than that of sucrose on a molar basis. Here we attempted to produce a protein with enhanced sweetness by removing negative charges on the interacting side of thaumatin with the taste receptor. We obtained a D21N mutant which, with a threshold value 31 nM is much swe...

Characterization of defense-related genes is critical for breeding disease-resistant poplar varieties and for better management and control of leaf rust disease. In the present study, full-length cDNAs of five Populus szechuanica defense-related (PsDR) genes, pathogen-related protein 1 (PsPR1), β-1,3-glucanase (PsGns), thaumatin-like protein 1 (PsTLP1), thaumatin-like protein 2 (PsTLP2), and ph...

Phloem exudate collected from hybrid poplar (Populus trichocarpa x Populus deltoides) was estimated to have more than 100 proteins, of which 48 were identified using LC-MS/MS. Comparative two-dimensional gel electrophoresis demonstrated that two phloem exudate proteins were significantly (P<0.05) upregulated 24 h after leaf wounding. These were identified as pop3/SP1 and a thaumatin-like protei...

Thaumatin, an intensely sweet-tasting protein, elicits sweet taste with a threshold of only 50 nM. Previous studies from our laboratory suggested that the complex model between the T1R2-T1R3 sweet receptor and thaumatin depends critically on the complementarity of electrostatic potentials. In order to further validate this model, we focused on three lysine residues (Lys78, Lys106, and Lys137), ...