Crystal structure of the sweet-tasting protein thaumatin II at 1.27 A

Journal Article · Fri Jul 08 00:00:00 EDT 2011 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/J.BBRC.2011.05.158· OSTI ID:22205001

Masuda, Tetsuya ^[1]; Ohta, Keisuke; Tani, Fumito ^[1]; Mikami, Bunzo ^[2]; Kitabatake, Naofumi ^[1]

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1. Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011 (Japan)
2. Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011 (Japan)

Highlights: {yields} X-ray crystallographic structure of sweet-tasting protein, thaumatin II, was determined at a resolution of 1.27 A. {yields} The overall structure of thaumatin II is similar to that of thaumatin I, but a slight shift of the C{alpha} atom of G96 in thaumatin II was observed. {yields} The side chain of two critical residues, 67 and 82, for sweetness was modeled in two alternative conformations. {yields} The flexibility and fluctuation of side chains at 67 and 82 seems to be suitable for interaction of thaumatin molecules with sweet receptors. -- Abstract: 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 A. Overall structure of thaumatin II is similar to thaumatin I, but a slight shift of the C{alpha} atom of G96 in thaumatin II was observed. Furthermore, the side chain of residue 67 in thaumatin II is highly disordered. Since residue 67 is one of two residues critical to the sweetness of thaumatin, the present results suggested that the critical positive charges at positions 67 and 82 are disordered and the flexibility and fluctuation of these side chains would be suitable for interaction of thaumatin molecules with sweet receptors.

• OSTI ID: 22205001
• Journal Information: Biochemical and Biophysical Research Communications, Vol. 410, Issue 3; Other Information: Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
CRYSTAL STRUCTURE
CRYSTALLOGRAPHY
FLEXIBILITY
FLUCTUATIONS
RECEPTORS
RESIDUES
SPATIAL RESOLUTION
X RADIATION