Increased Enzyme Secretion by 2-Deoxy-D-Glucose in Presence of Succinate by Suppression of Metabolic Enzymes in Termitomyces Clypeatus.

Pal, Swagata and Banik, Samudra Prosad and Ghorai, Shakuntala and Chowdhury, Sudeshna and Khowala, Suman (2011) Increased Enzyme Secretion by 2-Deoxy-D-Glucose in Presence of Succinate by Suppression of Metabolic Enzymes in Termitomyces Clypeatus. Carbohydrate Research, 346 (15). pp. 2426-2431.

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    Abstract

    Regulatory mode of secretion of proteins was detected for the industrial glycosidase, cellobiase, under secreting conditions (in presence of TCA cycle intermediates like succinate etc.) in the filamentous fungus Termitomyces clypeatus. The titers of key metabolic enzymes were investigated under secreting and nonsecreting conditions of growth and compared to the corresponding production of intra and extracellular levels of cellobiase. Results were compared in presence of 2-deoxy-D-glucose, a potent glycosylation inhibitor in the secreting media. Inclusion of 2-deoxy-D-glucose in presence of succinate caused about 10 to 100 times decrease in titers of the metabolic enzymes hexokinase, fructose-1,6-bisphosphatase, isocitrate lyase and malate dehydrogenase leading to increased secretion of cellobiase by more than 100 times. The intracellular concentration of cAMP (86-fold decrease in presence of 2-deoxy-D-glucose under secreting conditions) and turnover rate of proteins also dropped significantly. In this suppressed metabolic state, a 10-fold increase in the titer of the secreted cellobiase was noticed. The results indicated elucidation of carbon catabolite repression like phenomenon in the fungus under secreting conditions which was more pronounced by 2-deoxy-D-glucose. The interdependence between secretion and regulation of metabolic enzymes will help in better understanding of the physiology of these highly adapted organisms for increasing their secretion potential of glycosidases like cellobiase with high industrial value.

    Item Type: Article
    URI: http://www.eprints.iicb.res.in/id/eprint/1243
    Subjects: Drug Development/Diagnostics & Biotechnology
    Divisions: Indian Institute of Chemical Biology
    Depositing User: Ms Sutapa Ganguly
    Date Deposited: 18 Jan 2012 11:49
    Last Modified: 18 Jan 2012 11:49
    Official URL: http://dx.doi.org/10.1016/j.carres.2011.08.012
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