کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1926578 | 1536471 | 2008 | 5 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: A pyrroloquinoline quinine-dependent membrane-bound d-sorbitol dehydrogenase from Gluconobacter oxydans exhibits an ordered Bi Bi reaction mechanism A pyrroloquinoline quinine-dependent membrane-bound d-sorbitol dehydrogenase from Gluconobacter oxydans exhibits an ordered Bi Bi reaction mechanism](/preview/png/1926578.png)
A membrane-bound pyrroloquinoline quinine (PQQ)-dependent d-sorbitol dehydrogenase (mSLDH) in Gluconobacter oxydans participates in the oxidation of d-sorbitol to l-sorbose by transferring electrons to ubiquinone which links to the respiratory chain. To elucidate the kinetic mechanism, the enzyme purified was subjected to two-substrate steady-state kinetic analysis, product and substrate inhibition studies. These kinetic data indicate that the catalytic reaction follows an ordered Bi Bi mechanism, where the substrates bind to the enzyme in a defined order (first ubiquinone followed by d-sorbitol), while products are released in sequence (first l-sorbose followed by ubiquinol). From these findings, we proposed that the native mSLDH bears two different substrate-binding sites, one for ubiquinone and the other for d-sorbitol, in addition to PQQ-binding and Mg2+-binding sites in the catalytic center.
Journal: Archives of Biochemistry and Biophysics - Volume 477, Issue 2, 15 September 2008, Pages 206–210