glycoside hydrolase family 3 β-glucosidases and lytic polysaccharide monooxygenases
Gudmundsson, Mikael
(2014).
Structure and functional studies of plant cell wall degrading enzymes.
Diss. (sammanfattning/summary)
Uppsala :
Sveriges lantbruksuniv.,
Acta Universitatis Agriculturae Sueciae, 1652-6880
; 2014:83
ISBN 978-91-576-8114-0
eISBN 978-91-576-8115-7
[Doctoral thesis]
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54MB |
Abstract
Presently, plant biomass is considered as one of the major future renewable sources for the production of second-generation biofuels. While the first generation biofuels essentially are based on starch and sucrose rich feed stocks and which production may compete with food production, the second-generation biofuels may be based on lignocellulose as feedstock, which is less problematic from an ethical point of view. The degradation of carbohydrates in plant biomass to fermentable sugars requires the concerted action of several diverse classes of carbohydrate active enzymes (CAZymes) for a total and efficient conversion of the plant biomass. Through a carefully balanced synergism mechanistically different CAZymes are able to degrade the stable and recalcitrant pol- ymers in the plant cell walls, such as cellulose, to soluble and fermentable monosaccharides. It is crucial to study the properties and function of these enzymes if we want to strive for a sustainable production of chemicals and biofuels, as they serve as a reservoir of environmentally friendly molecular tools. The main focus of the research work presented in this thesis is biochemical and structure-function characterizations of two classes of CAZymes: fungal glycoside hydrolase family 3 (GH3) β-glucosidases, and bacterial lytic polysaccharide monooxygenases, often referred to as LPMOs. GH3 β- glucosidases catalyse the conversion of disaccharides, produced by other CAZymes e.g. cellulases, to glucose. H. jecorina Cel3A, R. emersonii Cel3A and N. crassa NcGH3-3 are three industrially relevant fungal GH3 β-glucosidases for which the structures have been determined using X-ray crystallographic methods. The H. jecorina Cel3A, R. em- ersonii Cel3A enzymes has also been characterized biochemically. The LPMOs act in the very initial stage of plant cell wall degradation and cleave glycosidic bonds in crys- talline polysaccharides via an oxidative mechanism, which facilitates access to new chain ends for other CAZymes. To elucidate the structural and biochemical properties of LPMOs with bacterial origin, the structure of an AA10 LPMO the LPMO10A from Enterococcus faecalis was determined using X-ray crystallography. Furthermore, structural changes of the active site metal configuration by so-called X-ray induced photoreduction, were determined. During this reduction process, which mimics the active enzyme, the bound active site copper atom is reduced from Cu(I) to Cu(II), which causes changes in the ligation configuration.
Authors/Creators: | Gudmundsson, Mikael | ||||||||||
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Title: | Structure and functional studies of plant cell wall degrading enzymes | ||||||||||
Subtitle: | glycoside hydrolase family 3 β-glucosidases and lytic polysaccharide monooxygenases | ||||||||||
Series Name/Journal: | Acta Universitatis Agriculturae Sueciae | ||||||||||
Year of publishing : | 20 November 2014 | ||||||||||
Depositing date: | 20 November 2014 | ||||||||||
Number: | 2014:83 | ||||||||||
Number of Pages: | 96 | ||||||||||
Papers/manuscripts: |
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Place of Publication: | Uppsala | ||||||||||
Publisher: | Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences | ||||||||||
ISBN for printed version: | 978-91-576-8114-0 | ||||||||||
ISBN for electronic version: | 978-91-576-8115-7 | ||||||||||
ISSN: | 1652-6880 | ||||||||||
Language: | English | ||||||||||
Additional Information: | |||||||||||
Publication Type: | Doctoral thesis | ||||||||||
Full Text Status: | Public | ||||||||||
Agris subject categories.: | P Natural resources > P06 Renewable energy resources X Agricola extesions > X50 Chemistry | ||||||||||
Subjects: | (A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Biochemistry and Molecular Biology | ||||||||||
Agrovoc terms: | lignocellulose, cell walls, biodegradation, beta glucosidase, hydrolases, crystallization, molecular biology | ||||||||||
Keywords: | Beta-glucosidase, Glycoside hydrolase, Lytic polysaccharide monooxygenase, Cellulose degradation, Structural biology, X-ray Crystallography | ||||||||||
URN:NBN: | urn:nbn:se:slu:epsilon-e-2233 | ||||||||||
Permanent URL: | http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-2233 | ||||||||||
ID Code: | 11663 | ||||||||||
Faculty: | NJ - Fakulteten för naturresurser och jordbruksvetenskap | ||||||||||
Department: | (NL, NJ) > Department of Chemistry and Biotechnology (140101-161231) | ||||||||||
External funders: | Energimyndigheten | ||||||||||
Deposited By: | Mikael Gudmundsson | ||||||||||
Deposited On: | 21 Nov 2014 15:01 | ||||||||||
Metadata Last Modified: | 02 Dec 2014 11:09 |
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