Research Progress and Prospects for Fructosyltransferases

Abstract

Fructosyltransferases can be used to produce fructooligosaccharides from sucrose and are obtained from different sources, mostly microorganisms and plants. Heterologous expression and several mutagenesis methods were applied to improve the production of fructosyltransferases. The structures and characteristics of fructosyltransferases were investigated. Immobilization and protein engineering can improve their characteristics. In this review, screening and mutagenesis of microorganisms, heterologous expression, purification, characterization, structural analysis, immobilization, and protein engineering of fructosyltransferases are discussed. Future prospects in this field are also considered.

Significant Improvement of Both Catalytic Efficiency and Stability of Fructosyltransferase from Aspergillus niger by Structure-Guided Engineering of Key Residues in the Conserved Sequence of the Catalytic Domain

“…Properties (e.g., catalytic activity) of enzymes can be usually improved by protein engineering methods (e.g., site-directed mutagenesis and directed evolution). However, there were few publications about enhancing the characteristics of FTases to overcome the limitations of wild-type enzymes using protein engineering methods . There was only one publication about improving transferase activity of FTase using site-directed mutagenesis.…”

“…This implies that the mutant C43N has a high catalytic efficiency, which has application potential in industrial production of FOS. Most publications about FTases were focused on production, determining characteristics, and immobilization . Han et al determined the kinetic parameters of FTase from A.…”

“…However, there were few publications about enhancing the characteristics of FTases to overcome the limitations of wild-type enzymes using protein engineering methods. 25 There was only one publication about improving transferase activity of FTase using site-directed mutagenesis. The transferase activity of FTase mutant (S196L) from Schwanniomyces occidentalis was increased by 3-fold that of WT, but the catalytic efficiency (k cat /K m ) of FTase mutant (S196L) was decreased by approximately 1000-fold that of WT.…”

“…Most publications about FTases were focused on production, determining characteristics, and immobilization. 25 Han et al determined…”

“…35 Generally, most FTases have optimal activity in the slightly acidic pH range (5.0−6.5). 25 The possible reasons for optimum transfructosylation at acidic pH was that the catalytic domains of these FTases included acidic amino acids, deprotonation of which were responsible for the catalytic process and structural integrity of enzymes. 1,37 Exceptionally, Aspergillus tamari FTase showed maximal activity at slight alkaline pH (7.41).…”