title: A GH57 4-α-glucanotransferase of hyperthermophilic origin with potential for alkyl glycoside production.
abstract: 4-α-Glucanotransferase (GTase) enzymes (EC 2.4.1.25) modulate the size of α-glucans by cleaving and reforming α-1,4 glycosidic bonds in α-glucans, an essential process in starch and glycogen metabolism in plants and microorganisms. The glycoside hydrolase family 57 enzyme (GTase57) studied in the current work catalyzes both disproportionation and cyclization reactions. Amylose was converted into cyclic amylose (with a minimum size of 17 glucose monomers) as well as to a spectrum of maltodextrins, but in contrast to glycoside hydrolase family 13 cyclodextrin glucanotransferases (CGTases), no production of cyclodextrins (C6-C8) was observed. GTase57 also effectively produced alkyl-glycosides with long α-glucan chains from dodecyl-β-D-maltoside and starch, demonstrating the potential of the enzyme to produce novel variants of surfactants. Importantly, the GTase57 has excellent thermostability with a maximal activity at 95 °C and an activity half-life of 150 min at 90 °C which is highly advantageous in this manufacturing process suggesting that enzymes from this relatively uncharacterized family, GH57, can be powerful biocatalysts for the production of large head group glucosides from soluble starch.
authors.affiliation: Biotechnology, Department of Chemistry, Lund University, Getingevägen 60, Lund, 22241, Sweden.
authors.forename: Catherine J
authors.initials: CJ
authors.lastname: Paul
authors.forename: Hans
authors.initials: H
authors.lastname: Leemhuis
authors.forename: Justyna M
authors.initials: JM
authors.lastname: Dobruchowska
authors.forename: Carl
authors.initials: C
authors.lastname: Grey
authors.forename: Linda
authors.initials: L
authors.lastname: Önnby
authors.forename: Sander S
authors.initials: SS
authors.lastname: van Leeuwen
authors.forename: Lubbert
authors.initials: L
authors.lastname: Dijkhuizen
authors.forename: Eva Nordberg
authors.initials: EN
authors.lastname: Karlsson
mesh_terms: D019611:Archaeoglobus fulgidus / Q000201:enzymology* / Q000235:genetics; D001711:Biotransformation; D004795:Enzyme Stability; D005960:Glucosides / Q000378:metabolism; D006004:Glycogen Debranching Enzyme System / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006027:Glycosides / Q000378:metabolism*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013213:Starch / Q000378:metabolism
chemical_list: D005960:Glucosides; D006004:Glycogen Debranching Enzyme System; D006027:Glycosides; D011994:Recombinant Proteins; C040358:dodecyl maltoside; D013213:Starch; C020569:4 alpha-glucanotransferase