2024-03-29T05:46:08Z
https://tsukuba.repo.nii.ac.jp/oai
oai:tsukuba.repo.nii.ac.jp:00025870
2022-04-27T08:53:04Z
160:868
3:62:5592:203
Reaction pathway of tryptophanase-catalyzed L-tryptophan synthesis from D-serine
島田, 秋彦
Shimada, Akihiko
Ozaki, Haruka
Saito, Takeshi
Fujii, Noriko
© 2011 Elsevier B.V.
NOTICE: this is the author's version of a work that was accepted for publication in Journal of chromatography. B. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of chromatography. B, Vol.879 Issue 29, Pages: 3289-3295. doi:10.1016/j.jchromb.2011.04.028.
Tryptophanase, L-tryptophan indole-lyase with extremely absolute stereospecificity, can change the stereospecificity in concentrated diammonium hydrogenphosphate solution. While tryptophanase is not inert to d-serine in the absence of diammonium hydrogenphosphate, it can undergo L-tryptophan synthesis from d-serine along with indole in the presence of it. It has been well known that tryptophanase synthesizes L-tryptophan from l-serine through a β-substitution mechanism of the ping-pong type. However, a metabolic pathway of L-tryptophan synthesis from d-serine has remained unclear. The present study aims to elucidate it. Diammonium hydrogenphosphate plays a role in the emergence of catalytic activity on d-serine. The salt gives tryptophanase a small conformational change, which makes it possible to catalyze d-serine. Tryptophanase-bound d-serine produces L-tryptophan synthesis by β-replacement reaction via the enzyme-bound aminoacrylate intermediate. Our result will be valuable in studying the origin of homochirality.
Elsevier
2011-11
eng
journal article
http://hdl.handle.net/2241/114816
https://tsukuba.repo.nii.ac.jp/records/25870
21601540
10.1016/j.jchromb.2011.04.028
1570-0232
AA11656178
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences
879
29
3289
3295
https://tsukuba.repo.nii.ac.jp/record/25870/files/JCB_879-29.pdf
application/pdf
632.6 kB
2013-12-25