[Dynamics of activity of the key enzymes of polyhydroxyalkanoate metabolism in Ralstonia eutropha].
The dynamics of accumulation of polyhydroxybutyrate (PHB) and the activities of the key enzymes of PHB metabolism (beta-ketothiolase, acetoacetyl-CoA reductase, PHA synthase, D-hydroxybutyrate dehydrogenase, and PHA depolymerase) in the hydrogen bacterium Ralstonia eutropha B5786 were studied under various conditions of carbon nutrition and substrate availability. The highest activities of beta-ketothiolase, acetoacetyl-CoA reductase, and PHA synthase were recorded at the stage of acceleration of PHB synthesis. The activities of enzymes catalyzing PHB depolymerization (PHB depolymerase and D-hydroxybutyrate dehydrogenase) were low, being expressed only at stimulated endogenous PHB degradation. The change of carbon source (CO2 or fructose) did not cause any marked changes in the time course of enzyme activity.
Volova
T G
TG
Institute of Biophysics, Siberian Division, Russian Academy of Sciences, Akademgorodok, Krasnoyarsk, 660036 Russia. volova@ibp.ru
Kalacheva
G S
GS
Gorbunova
O V
OV
Zhila
N O
NO
D000102:Acetyl-CoA C-Acyltransferase / Q000737:chemistry / Q000378:metabolism; D000217:Acyltransferases / Q000737:chemistry / Q000378:metabolism; D000429:Alcohol Oxidoreductases / Q000737:chemistry / Q000378:metabolism; D002265:Carboxylic Ester Hydrolases / Q000737:chemistry / Q000378:metabolism; D003470:Culture Media; D020118:Cupriavidus necator / Q000201:enzymology* / Q000254:growth & development; D006884:Hydroxybutyrate Dehydrogenase / Q000737:chemistry / Q000378:metabolism; D006885:Hydroxybutyrates / Q000378:metabolism*; D011108:Polymers
D003470:Culture Media; D006885:Hydroxybutyrates; D011108:Polymers; D000429:Alcohol Oxidoreductases; D006884:Hydroxybutyrate Dehydrogenase; C023744:acetoacetyl-CoA reductase; D000217:Acyltransferases; C077225:poly(3-hydroxyalkanoic acid) synthase; D000102:Acetyl-CoA C-Acyltransferase; D002265:Carboxylic Ester Hydrolases; C077226:poly(3-hydroxyalkanoic acid) depolymerase