8i2q

Publication Abstract from PubMed

The trisaccharide 1-kestose, a major constituent of fructooligosaccharide, has strong prebiotic effects. We used high-performance liquid chromatography and 1H nuclear magnetic resonance spectroscopy to show that BiBftA, a beta-fructosyltransferase belonging to glycoside hydrolase family 68, from Beijerinckia indica subsp. indica catalyzes transfructosylation of sucrose to produce mostly 1-kestose and levan polysaccharides. We substituted His395 and Phe473 in BiBftA with Arg and Tyr, respectively, and analyzed the reactions of the mutant enzymes with 180 g/L sucrose. The ratio of the molar concentrations of glucose and 1-kestose in the reaction mixture with wild-type BiBftA was 100:8.1, whereas that in the reaction mixture with the variant H395R/F473Y was 100:45.5, indicating that H395R/F473Y predominantly accumulated 1-kestose from sucrose. The X-ray crystal structure of H395R/F473Y suggests that its catalytic pocket is unfavorable for binding of sucrose while favorable for transfructosylation.

Characterization and alteration of product specificity of Beijerinckia indica subsp. indica beta-fructosyltransferase.,Li D, Miyasaka Y, Kubota A, Kozono T, Kitano Y, Sasaki N, Fujii T, Tochio T, Kadota Y, Nishikawa A, Tonozuka T Biosci Biotechnol Biochem. 2023 Aug 23;87(9):981-990. doi: 10.1093/bbb/zbad074. PMID:37280168^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.