|Glycerol-3-phosphatase and the control of glycerol metabolism in Dunaliella tertiolecta cells|Belmans, D.; Van Laere, A. (1988). Glycerol-3-phosphatase and the control of glycerol metabolism in Dunaliella tertiolecta cells. Arch. Microbiol. 150(2): 109-112. dx.doi.org/10.1007/BF00425148
In: Archives of Microbiology. Springer: Heidelberg; Berlin. ISSN 0302-8933, more
CalciumDunaliella tertiolectaEnzyme kineticsGlycerolGlycerol-3-phosphataseMetabolic regulationOsmoacclimation
|Authors|| || Top |
- Belmans, D.
- Van Laere, A.
Glycerol-3-phosphatase (EC 220.127.116.11.1) was studied by following the release of radioactive glycerol from L-(U-14C)glycerol-3-phosphate in Dunaliella tertiolecta enzyme extracts. The reaction showed a neutral pH optimum and had an absolute requirement for Mg2+. The substrate saturation curve was hyperbolic with an apparent Km value for glycerol-3-phosphate of 0.7 mM in the absence of phosphate. Inorganic orthophosphate was a competitive inhibitor of the enzyme with an estimated Kj of 0.1 mM. The glycerol-3-phosphatase reaction was blocked nearly completely by millimolar Ca2+ concentrations. Ca2+ inhibition did not depend on the presence of calmodulin in the reaction medium. The characteristics of glycerol-3-phosphatase are discussed in relation to the regulation of the cyclic glycerol metabolism in Dunaliella cells during periods of osmotic stress.