Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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Record number 343217
Title Characterisation of a 1,4-ß-fucoside hydrolase degrading colanic acid
Author(s) Verhoef, R.P.; Beldman, G.; Schols, H.A.; Siika-aho, M.; Ratto, M.; Buchert, J.; Voragen, A.G.J.
Source Carbohydrate Research : an international journal 340 (2005)11. - ISSN 0008-6215 - p. 1780 - 1788.
Department(s) Food Chemistry Group
Publication type Refereed Article in a scientific journal
Publication year 2005
Keyword(s) salmonella-typhimurium - escherichia-coli - m-antigen - paper - exopolysaccharide
Abstract A novel colanic acid-degrading enzyme was isolated from a mixed culture filtrate obtained by enrichment culturing of a compost sample using colanic acid as carbon source. The enzyme was partially purified resulting in a 17-fold increase in specific activity. Further purification by Native PAGE revealed that the enzyme is part of a high-molecular weight multi protein complex of at least six individual proteins. The enzyme showed a temperature optimum at 50 °C while after 5 h at 50 °C and pH 7 still 70% of the total activity was left. The pH optimum was found to be pH 7. Analysis of the degradation products showed that the enzyme is a novel 1,4-ß-fucoside hydrolase that liberates repeating units of colanic acid with varying degrees of acetylation. Km and Vmax of the enzyme were determined against the native substrate as well as its de-O-acetylated and depyruvated forms. Compared to the native substrate the affinity of the enzyme for the modified substrates was much lower. However, for the de-O-acetylated sample a dramatic increase in catalytic efficiency was observed. The native form of the substrate showed substrate inhibition at high concentrations, probably due to the formation of nonproductive substrate complexes. Removal of the acetyl groups probably prevents this effect resulting in a higher catalytic efficiency.
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