Lipase activation energy

The catalysts were found to be stable up to 323 K without any deactivation. An activation energy of 45 kJ/mol was found for the free enzyme, 41 kJ/mol for the immobilized lipase, indeed confirming the absence of mass transfer limitations. 

When lipids are required by the body for energy, adipose cell hormone-sensitive lipase (activated by epinephrine, and inhibited by insulin) initiates degradation of stored triacyl glycerol. 

Topiramate, felbamate, and zonisamide are associated with weight loss. In animals topiramate reduced food intake, but also reduced energy disposition in the absence of reduced intake. In addition, topiramate increased lipoprotein lipase activity in adipose tissue, possibly reflecting enhanced regulatory thermogenesis. In humans and animals topiramate reduces leptin concentrations. With felbamate weight loss is almost always associated with... 

In the capillaries of these tissues, the extracellular enzyme lipoprotein lipase, activated by apoC-II, hydrolyzes triacylglycerols to fatty acids and glycerol (step ), which are taken up by cells in the target tissues (step (7)) In muscle, the fatty acids are oxidized for energy in adipose tissue, they are reesterified for storage as triacylglycerols (step (8)). 

Generally, alkali-catalyzed transesterification is conducted at near the boiling point of the alcohol, but enzyme-catalyzed transesterification is performed at a low temperature to prevent the loss of lipase activity [9]. The low reaction temperature was also found to be desirable, as the reaction temperature was closely related to the energy cost inherent to the process of biodiesel production [3]. 

Within the developing embryo, lipoprotein lipase activity is high in both heart and adipose tissue at EI4 but is absent from liver and brain. A big increase in activity occurs in adipose tissue between EI2 and EI6 and this coincides with the period of lipid uptake from the yolk and deposition in the adipocytes. More than 90% of the energy required by the developing embryo is obtained from oxidation of fatty acids present in yolk triglycerides. A further increase in lipoprotein lipase activity also occurs on hatching (Speake, Noble McCartney, 1993). 

Fig. 6. The effect of tauiocholate on the activation energy of triolein hydrolysis by pancreatic lipase. V = initial rate of reaction, T = absolute temperature — no taurocholate added, O—taurocholate added. The activation energy in the presence of taurocholate is 5240 cal/mole (214).

Unless the catalytic surface of the enzyme is altered, an environmental change should theoretically have no effect on the activation energy Lipase, trypsin, and pepsin follow the Arrhenius equation, but below 0°... 

Further studies on the mechanistic limitations in the lipase-catalyzed ringopening polymerization of s-CL in toluene with monomethoxy-poly(ethylene glycol) and water as initiators were carried out [93]. The apparent activation energy for the lipase-B-catalyzed e-CL polymerization in toluene is estimated to be 2.88kcal/mol. On the other hand, the activation energy for the aluminum-alkoxide-catalyzed -CL polymerization in toluene is 10.3 kcal/mol [89]. 

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