Thaumatin, an intensely sweet-tasting protein, elicits a sweet taste sensation at 50 nM. Here the X-ray crystallographic structure of one of its variants, thaumatin II, was determined at a resolution of 1.27 Å. Overall structure of thaumatin II is similar to thaumatin I, but a slight shift of the Cα atom of G96 in thaumatin II was observed. Furthermore, the side chain of residue 67 in thaumatin...

Thaumatin, an intensely sweet-tasting plant protein, elicits a sweet taste at a concentration of 50 nM. The crystal structure of a recombinant form of thaumatin I produced in the yeast Pichia pastoris has been determined to a resolution of 1.1 Å. The model was refined with anisotropic B parameters and riding H atoms. A comparison of the diffraction data and refinement statistics for recombinant...

In previous work, we showed that thaumatin, an intensely sweet protein, binds to certain formed elements in taste pores of Rhesus monkey foliate papillae, namely, microvilli and small vesicles shed from microvilli, in addition to amorphous secretions (Farbman et al., 1987). We suggested that the taste bud responds to a thaumatin stimulus by shedding the small vesicles containing fragments of mi...

Thaumatin, an intensely sweet protein, is the major proteinaciouscompnentinthe arils ofThaumatococcusdaniellii [l].Thaumatinisamemberofafamilyofatleastfiveisoforms, separable on cation exchange chromatography and all with a molecular weight of approx. 22 kDa and possessing eight disulphide bridges. Thaumatin I and II are derived from distinct genes, the other subforms may result from post-trans...

matococcus daniellii Benth.i) The moleculaT mass of the protein is 22 kDa and the higher order structure of the protein is maintained by eight disulfide bridges.2・3) Thaumatin is the sweetest substance for man and is, on a molar basis, 100,OOO times sweeter than sucrose.i) Today, thaumatin is used commercially for its intense sweetness, taste masking, fiavor enhancement, and synergistic propert...

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...

Two different strains, Aspergillus awamori TGDTh-4 and A. awamori TGP-3 overexpressing a synthetic gene encoding the plant sweet protein thaumatin, showed an unfolded protein response. To facilitate protein secretion, the chaperone BiPA gene was expressed in A. awamori under control of the strong constitutive promoter of the gpdA gene. A good correlation was observed between the level of the bi...

To clarify the structural basis for the sweetness of thaumatin I, lysine-modified derivatives and carboxyl-group-modified derivatives were prepared by chemical modification followed by chromatographic purification. The sweetness of derivatives was evaluated by sensory analysis. Phosphopyridoxylation of lysine residues Lys78, Lys97, Lys106, Lys137 and Lys187 markedly reduced sweetness. The inten...

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), ...

SAR in plants is found to correlate with induction of a set of putative defense genes including PR proteins (Linthorst, 1991). The PR proteins are a group of extracellular proteins that are induced by different phytopathogens such as viruses, bacteria, and fungi, and SAR-inducing compounds such as salicylic acid and 2,6-dichloroisonicotinic acid (Bol et al., 1990; Uknes et al., 1992). These pro...