Synthesis of New Hyper-Branched α-Glucans from Sucrose by Lactobacillus reuteri 180 Glucansucrase Mutants

Xiangfeng Meng, Justyna M Dobruchowska, Tjaard Pijning, Gerrit J Gerwig, Lubbert Dijkhuizen

Research output: Contribution to journalArticleAcademicpeer-review

18 Citations (Scopus)


α-Glucans produced by glucansucrase enzymes of lactic acid bacteria attract strong attention as novel ingredients and functional biopolymers in the food industry. In the present study, α-helix 4 amino acid residues D1085, R1088 and N1089 of glucansucrase GTF180 of Lactobacillus reuteri 180 were targeted for mutagenesis both jointly and separately. Analysis of the mutational effects on enzyme function revealed that all D1085 and R1088 mutants catalyzed the synthesis of hyper-branched α-glucans with 15-22% branching (α1→3,6) linkages, compared to 13% in the wild-type GTF180. In addition, besides native (α1→6) and (α1→3) linkages, all the mutations introduced a small amount of (α1→4) linkages (5% at most) in the polysaccharides produced. We conclude that α-helix 4 residues, especially D1085 and R1088, constituting part of the +2 acceptor binding subsite, are important determinants for the linkage specificity. The new hyper-branched α-glucans provide very interesting structural diversities and may find applications in the food industry.

Original languageEnglish
Pages (from-to)433-442
Number of pages10
JournalJournal of Agricultural and Food Chemistry
Issue number2
Early online date19-Dec-2015
Publication statusPublished - 20-Jan-2016


  • enzyme mutation
  • glucansucrase
  • hyperbranched alpha-glucan
  • product specificity
  • GTF180
  • Lactobacillus reuteri

Cite this