GtfC Enzyme of Geobacillus sp. 12AMOR1 Represents a Novel Thermostable Type of GH70 4,6-α-Glucanotransferase That Synthesizes a Linear Alternating (α1 → 6)/(α1 → 4) α-Glucan and Delays Bread Staling
| Autor: | Anastasia Chrysovalantou Chatziioannou, Lizette A A C M Oudhuis, Stevan E van der Hoek, Hans Leemhuis, Evelien M Te Poele, Wouter J Duisterwinkel, Joana Gangoiti, Gerrit J. Gerwig, Lubbert Dijkhuizen |
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| Přispěvatelé: | Molecular Immunology, Host-Microbe Interactions |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
chemistry.chemical_classification
biology Starch α-glucanotransferase thermostable General Chemistry Maltose Exiguobacterium biology.organism_classification Geobacillus stomatognathic diseases chemistry.chemical_compound Enzyme NMR spectroscopy Biochemistry chemistry Hydrolase Glycosyl antistaling maltose General Agricultural and Biological Sciences Glucan |
| Zdroj: | Journal of Agricultural and Food Chemistry, 69(34), 9859-9868. AMER CHEMICAL SOC |
| ISSN: | 0021-8561 |
| Popis: | Starch-acting α-glucanotransferase enzymes are of great interest for applications in the food industry. In previous work, we have characterized various 4,6- and 4,3-α-glucanotransferases of the glycosyl hydrolase (GH) family 70 (subfamily GtfB), synthesizing linear or branched α-glucans. Thus far, GtfB enzymes have only been identified in mesophilic Lactobacilli. Database searches showed that related GtfC enzymes occur in Gram-positive bacteria of the genera Exiguobacterium, Bacillus, and Geobacillus, adapted to growth at more extreme temperatures. Here, we report characteristics of the Geobacillus sp. 12AMOR1 GtfC enzyme, with an optimal reaction temperature of 60 °C and a melting temperature of 68 °C, allowing starch conversions at relatively high temperatures. This thermostable 4,6-α-glucanotransferase has a novel product specificity, cleaving off predominantly maltose units from amylose, attaching them with an (α1 → 6)-linkage to acceptor substrates. In fact, this GtfC represents a novel maltogenic α-amylase. Detailed structural characterization of its starch-derived α-glucan products revealed that it yielded a unique polymer with alternating (α1 → 6)/(α1 → 4)-linked glucose units but without branches. Notably, this Geobacillus sp. 12AMOR1 GtfC enzyme showed clear antistaling effects in bread bakery products. |
| Databáze: | OpenAIRE |
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