Endo-P-l,4-glucanases

We can give here an example of topolytic activity of ceUulases (which means the capability of the enzyme to run reactions on the surface of insoluble substrate without deep destmction of cellulose structure), particularly of endo-P-l,4-glucanases (EGs). These enzymes have hydrolytic activities toward polyglucans containing p-l,4-glycosidic bonds, which include cotton and wood cellulose, different soluble cellulose derivatives, p-glucans of oat and barley, and other polysaccharides. Hydrolysis of cellulose by EGs occurs by endo-depolymerization mechanism. 

Fig. 6. A purified endo-p-l,4-glucanase converts the xyloglucan of sycamore cell walls into oligosaccharides a, b and c. A mixture of glycosidases converts oligosaccharide b into oligosaccharide d and thereby establishes the point of attachment of the fucosyl-galactosyl disaccharide present in oligosaccharides b and c. Experimental details are in ref. (31)...

Trainotti, L Spolaore, S Pavanello, A Baldan, B Casadoro, G. A novel E-type endo-P-l,4-glucanase with a putative cellulose-binding domain is highly expressed in ripening strawberry fruits. Plant Molecular Biology, 1999, 40(2). 

Enzymes involved in rp endo- 3-l,4-glucanase, exo-P-l,4-cellobiohydrolase. Enzymes involved in r2 exo-P-l,4-cellobiohydrolase, exo-P-l,4-glucan glucohydrolase. Enzymes involved in r3 P-bludosidse or cellobiases. 

The effects of temperature on the synthesis of a cellulase (endo-P-l,4-D-glucanase) by cultures of the compost fungus Chaetomium thermophile have been investi-gated. Although this fungus grows on a number of carbohydrates, synthesis of the cellulase activity was induced only in the presence of cellulose or D-xylan. The enzyme exhibited optimal activity at 58 °C and is most stable at pH 6.0. 

The synthesis of polysaccharide hydrolases, including endo-p-l,4-D-glucanases, by germinating rye has been examined. ... 

Kim CH (1995) Characterization and substrate specificity of an endo-p-l,4-D-glucanase I (Avicelase I) from an extracellular multienzyme complex of Bacillus circulans. Appl Environ Microbiol 61 959-965... 

Adlakha N, Sawant S, Anil A, Lali A, Yazdani SS. (2012). Specific fusion of p-l,4-endo-glucanase and p-l,4-glncosidase enhances cellulolytic activity and helps in channeling of intermediates. Appl Environ Microbiol, 78, 7447-7454. 

Biely, P., Mislovicova, D., and Toman, R., Soluble chromogenic substrates for the assay of endo-1,4-beta-xylanases and endo-l,4-beta-glucanases. Analytical Biochem 1985, 144(1), 142-146. 

Brummell DA, Lashbrook CC, Bennett AB (1994) Plant endo-l,4-P-D-glucanases. In Himmel ME, Baker JO, Overend RP (eds) Enzymatic conversion of biomass for fuels production. American Chemical Society, Washington, DC, p 100... 

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