学術雑誌論文

学術雑誌論文

text

Journal of Biological Chemistry. 2001, 276(14), p. 11062-11071

Entropic stabilization of the tryptophan synthase α-subunit from a hyperthermophile, Pyrococcus furiosus : X-ray analysis and calorimetry

American Society for Biochemistry and Molecular Biology

英語

text

2001-04

https://doi.org/10.1074/jbc.M009987200

This research was originally published in Journal of Biological Chemistry. Yuriko Yamagata, Kyoko Ogasahara, Yusaku Hioki, Soo Jae Lee, Atsushi Nakagawa, Haruki Nakamura, Masami Ishida, Seiki Kuramitsui, and Katsuhide Yutani. Entropic stabilization of the tryptophan synthase α-subunit from a hyperthermophile, Pyrococcus furiosus : X-ray analysis and calorimetry. J. Biol. Chem. 2001; 276, 11062-11071. © the American Society for Biochemistry and Molecular Biology.

The structure of the tryptophan synthase α-subunit from Pyrococcus furiosus was determined by x-ray analysis at 2.0-Å resolution, and its stability was examined by differential scanning calorimetry. Although the structure of the tryptophan synthase α_2β_2 complex from Salmonella typhimurium has been already determined, this is the first report of the structure of the α-subunit alone. The α-subunit from P. furiosus (Pf-α-subunit) lacked 12 and 6 residues at the N and C termini, respectively, and one residue each in two loop regions as compared with that from S. typhimurium (St-α-subunit), resulting in the absence of an N-terminal helix and the shortening of a C-terminal helix. The structure of the Pf-α-subunit was essentially similar to that of the St-asubunit in the α_2β_2 complex. The differences between both structures were discussed in connection with the higher stability of the Pf-α-subunit and the complex formation of the α- and β-subunits. Calorimetric results indicated that the Pf-α-subunit has extremely high thermostability and that its higher stability is caused by an entropic effect. On the basis of structural information of both proteins, we analyzed the contributions of each stabilization factor and could conclude that hydrophobic interactions in the protein interior do not contribute to the higher stability of the Pf-α-subunit. Rather, the increase in ion pairs, decrease in cavity volume, and entropic effects due to shortening of the polypeptide chain play important roles in extremely high stability in Pf-α-subunit.

© the American Society for Biochemistry and Molecular Biology.

73647

Entropic stabilization of the tryptophan synthase α-subunit from a hyperthermophile, Pyrococcus furiosus : X-ray analysis and calorimetry

American Society for Biochemistry and Molecular Biology

英語

2001-04

Journal of Biological Chemistry

276

14

11062

11071

https://doi.org/10.1074/jbc.M009987200

11118452

https://hdl.handle.net/11094/73647