Biochemical characterization of two GH70 family 4,6-α-glucanotransferases with distinct product specificity from Lactobacillus aviarius subsp. aviarius DSM 20655Meng, X., Gangoiti, J., de Kok, N., van Leeuwen, S. S., Pijning, T. & Dijkhuizen, L., 1-Jul-2018, In : Food Chemistry. 253, p. 236-246 11 p., j.foodchem.2018.01.154.
Research output: Contribution to journal › Article › Academic › peer-review
Nine GtfB-like 4,6-α-glucanotransferases (4,6-α-GTs) (represented by GtfX of L. aviarius subsp. aviarius DSM 20655) were identified to show distinct characteristics in conserved motifs I-IV. In particular, the "fingerprint" Tyr in motif III of these nine GtfB-type 4,6-α-GTs was found to be replaced by a Trp. In L. aviarius subsp. aviarius DSM20655, a second GtfB-like protein (GtfY), containing the canonical GtfB Tyr residue in motif III, was located directly upstream of GtfX. Biochemical characterization revealed that both GtfX and GtfY showed GtfB-like 4,6-α-GT activity, cleaving (α1→4) linkages and catalyzing the synthesis of (α1→6) linkages. Nonetheless, they differ in product specificity; GtfY only synthesizes consecutive (α1→6) linkages, yielding linear α-glucan products, but GtfX catalyzes the synthesis of (α1→6) linkages predominantly at branch points (22%) rather than in linear segments (10%). The highly branched α-glucan produced by GtfX from amylose V is resistant to digestion by α-amylase, offering great potential as dietary fibers.
|Number of pages||11|
|Publication status||Published - 1-Jul-2018|
- alpha-glucan, 4,6-alpha-Glucanotransferase, Family GH70, Lactic acid bacteria, Glucansucrase, Polysaccharides, LACTIC-ACID BACTERIA, STRUCTURAL-CHARACTERIZATION, MOLECULAR CHARACTERIZATION, GLUCANSUCRASE GTF180, ACTIVE-SITE, REUTERI 121, ENZYMES, GLUCAN, STARCH, GTFB