ISSN:
1432-2048
Keywords:
Commelina
;
Epidermis
;
Phosphoenolpyruvate carboxylase
;
Stoma
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Phosphoenolpyruvate (PEP) carboxylase activity in epidermal extracts of Commelina communis has been compared in the presence of malate and glucose-6-phosphate. The activity of PEP carboxylase was inhibited by increasing malate concentrations at several substrate (PEP) concentrations and changes in both the apparent K m (PEP) and V max values in the presence of malate suggested the occurence of mixed-type inhibiton. In the presence of glucose-6-phosphate no increase in enzyme activity was observed, although there was a slight decrease in the K m (PEP). However, glucose-6-phosphate appeared to alleviate the inhibition caused by malate. The possible implications of these properties in the control of malate production in guard cells is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00394470
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