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

OnderzoeksoutputAcademicpeer review

19 Citaten (Scopus)

Samenvatting

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.

Originele taal-2English
Pagina's (van-tot)433-442
Aantal pagina's10
TijdschriftJournal of Agricultural and Food Chemistry
Volume64
Nummer van het tijdschrift2
Vroegere onlinedatum19-dec-2015
DOI's
StatusPublished - 20-jan-2016

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