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...

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...

The protein composition of the grape (Vitis vinifera cv Muscat of Alexandria) berry was examined from flowering to ripeness by gel electrophoresis. A protein with an apparent molecular mass of 24 kD, which was one of the most abundant proteins in extracts of mature berries, was purified and identified by amino acid sequence to be a thaumatin-like protein. Combined cDNA sequence analysis and ele...

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...

Pathogenesis-related proteins from intercellular fluid washings of stressed barley (Hordeum vulgare L.) leaves were analyzed to determine their binding to various water-insoluble polysaccharides. Three proteins (19, 16, and 15 kD) bound specifically to several water-insoluble beta-1,3-glucans. Binding of the barley proteins to pachyman occurred quickly at 22 degreesC at pH 5.0, even in the pres...

Thaumatin-like proteins (TLPs) are involved in the plant defense response against pathogens, and most of them exhibit antifungal activity. However, role TLPs pathogen-induced responses spruce is not fully understood. In this study, four TLP genes encoding thaumatin-like protein, designated as PlTLP1–4, were isolated identified from Picea likiangensis needles. Sequence analysis showed that PlTLP...

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...