Glucansucrase (Alpha-glucanotransferase) from Lactobacillus reuteri

gtfa163

220,00490,00

A moderately thermostable Glucansucrase (4,6-Alpha-Glucanotransferase, reuteransucrase) from Lactobacillus reuteri strain 121

 


SKU: gtfa163.
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Description

Product Gtfa163A moderately thermostable Glucansucrase (4,6-Alpha-Glucanotransferase, reuteransucrase). The enzyme transfers glucose units from sucrose to make a highly branched, high molecular weight alpha-D-Glucan with α(1→4) glucosidic linkages and also some α(1→6) linked glucosyl units.

The enzyme is available for purchase as 100 or 500 microliter solution (1 mg/ml).

Product Gtfa163S | 100 microliter | EUR 195

Product Gtfa163L | 500 microliter | EUR 490

For purchase select size and add to cart above.

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For further information read more below or download the product sheet

 

Enzyme activity: Gtfa163 Glucansucrase (Reuteransucrase) catalyses the transfer of glucose from sucrose to make a highly branched, high-molecular-weight α-D-glucan with α(1→4) glucosidic linkages but also some α(1→6)-linked glucosyl units and 4,6-disubstituted glucosyl units at the branching points.

As an example, glucose transferase activity was determined at 50°C for 60 hours in a 25 mM sodium acetate buffer at pH 4.7, containing 1 mM CaCl2 and 100 mM sucrose. This gave complete utilization of the sucrose with about 75% going into α-D-glucan. 

Activity determination: Glucansucrase activity was determined at 50°C in a 25 mM sodium acetate buffer at pH 4.7, containing 10 mM CaCl2 and 30 nM enzyme.

Unit definition: One unit (U) of enzyme activity is the amount that leads to the release of 1 μmol of fructose from sucrose per minute.

Synonyms: glycoside hydrolase, glucosyltransferase, 4,6-alpha-Glucanotransferase, Reuteransucrase

Protein family: Glycosyl hydrolase family 70 ( GH70 ) – GH-H clan – CAZy database GH70 family

Enzyme classification: EC 2.4.1.-

Source: The lactic acid bacteria Lactobacillus reuteri strain 121

Protein sequence: NBCI protein entry

Structural information: The crystal structure of Gtfa163 Glucansucrase (Reuteransucrase) from Lactobacillus reuteri121 has been determined and shown here in Figure 1 (Pijning et al. 2012). – PDB entry 4AMC

Animation of the crystal structure of Glucansucrase from Lactobacillus reuteri

Figure 1: Crystal structure of Gtfa163 Glucansucrase

(truncated form comprising residues 745-1763 including catalytic domain)  

Applications:

Exopolysaccharide synthesis:

The enzyme produced a α-D-glucan polymer (MW 3.5×106 Da) with a composite structure, that includes all identified structural elements, as shown in Fig. 2 below (van Leeuwen et al 2008)

 

Branched polysaccharide product of Gtfa163

Figure 2. Composite model of a alpha-D-glucan product made by Gtfa163 Glucansucrase

 

Oligosaccharides from sucrose:

With only sucrose present, and before branching starts, the enzyme activity will yield a linear oligosaccharides via alternating α(1→4) and α(1→6) linkages. Malto-oligosaccharides (DP2-DP6) in the absence of sucrose are slow substrates. With high concentration of sucrose the formation of low-molecular-mass oligosaccharides was favoured over high-molecular-mass polysaccharides.

Properties of Gtfa163 Glucansucrase:

Gtfa163 - Activity vs. Temperature profile 

Figure 3. Temperature optimum: the enzyme has optimum activity around 50°C (Kralj et al. 2004).

 

 

 Activity of Glucansucrase as a function of pH

Figure 4. pH profile: Solid line, transferase activity; dashed line, hydrolysis activity (Kralj et al. 2004).

References:

Van Leeuwen SS, Kralj S, van Geel-Schutten IH, Gerwig GJ, Dijkhuizen L, Kamerling JP (2008) Structural analysis of the α-D-glucan (EPS35-5) produced by the Lactobacillus reuteri strain 35-5 glucansucrase GTFA enzyme. Carbohydr. Res. 343: 1251–1265.

Kralj S, van Geel-Schutten GH, van der Maarel MJEC & Dijkhuizen L (2004) Biochemical and molecular characterization of Lactobacillus reuteri 121 reuteransucrase. Microbiology 150: 2099–2112.

Leemhuis H, Pijning T, Dobruchowska JM, van Leeuwen SS, Kralj S, Dijkstra BW, Dijkhuizen L. (2013) Glucansucrases: Three-dimensional structures, reactions, mechanism, α-glucan analysis and their implications in biotechnology and food applications. J. Biotechnol. 163:250-272.

Pijning T, Vujicic-Zagar A, Kralj S, Dijkhuizen L & Dijkstra BW (2012) Structure of the α-1,6/α-1,4-specific glucansucrase GTFA fromLactobacillus reuteri 121. Acta Cryst. F68: 1448-1454.

Additional information

Size and price

100 microliters – EUR 220, 500 microliters – EUR 490