English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

LIMA, M. Z. T. Functional and Structural studies of the fructosyltransferases enzymes from the families 32 and 68 of glycoside hydrolases 2015. 163 p. Dissertação (Mestrado em Ciências) – Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, 2015. The search for beneficial substances to human health has driven the development of researches on the study of enzymes and their products through bioprocess optimization. One of the main components used as a basis for functional food industry are carbohydrates called fructooligosaccharides (FOS) derived from sucrose. These are synthesized by enzymes called fructosyltransferases which can be found in plants, bacteria and fungi. The FOS has attracted great interest of the industry due to its physiological and biomodulator properties. Because it is non-digestible polysaccharides prebiotics, have the ability to selectively stimulate the growth of bifidobacteria and lactobacilli, assisting in the prevention of tooth decay and colon cancer in humans. They can also contribute to decrease total cholesterol and triglycerides in the blood, to promote the absorption of calcium and magnesium and can be used in diets with dietary restrictions, because they are low-calorie sugars presenting high nutritional value. Considering there are different forms of FOS synthesized by different mechanisms, the present work attempts to make structural and functional characterization of a set of 13 fructosyltransferases of bacteria and fungi. The target genes were cloned and the enzymes were expressed and purified. Structural testing of X-ray crystallography and enzymatic activity, including sucrose hydrolysis and polymerization were carried out for a better understanding of the molecular basis involved in substrate recognition. Eight enzymes, two βfrutofuranosidases B. adolescentis, three sucrose-6-phosphate hydrolase of B. licheniformis and L. gasseri and A. niger invertase, were crystallized and the enzymes from B. adolescentis and from L. gasseri had their structures determined and their catalytic site mapped. These are similar to each other and present in their structure one β-propeller region which was identified as catalytic site, connected to one β-sandwich module. Both enzymes showed hydrolytic activity of the sucrose and L. gasseri showed the formation of FOS, 1-kestose and nystose with 1 M sucrose concentrations and times of 8 and 12 hours of incubation. These studies together with the analysis of other enzymes will enable the improvement in large-scale production, besides the optimization and control of these processes for the production of FOS.

Estudos funcionais e estruturais de enzimas frutosiltransferases das famílias 32 e 68 de hidrolases de glicosídeos