II' Regulation by Allosteric Control

1
II. Regulation by Allosteric Control

• Palmitoyl CoA inhibits fatty acid
  synthesis by
• allosteric inhibition of acetyl CoA
  carboxylase
• Decreased fructose 2,6-bisphosphate which
• results in a decrease in
  phosphofructokinase-1
• activity and increase in
  fructose-1,6-bisphosphatase

2
III. Hormonal Control with Insulin

• Binding of the insulin to the plasma
  membrane results in the subsequent
  dephosphorylation of enzymes by phosphoprotein
  phosphatases.
• a. Acetyl CoA carboxylase ( activated)
• b. Hormone sensitive lipase ( inactivated)
• c. Pyruvate dehydrogenase ( activated)
• With the following results
• a. Increased fatty acid synthesis
• b. Decreased gluconeogenesis
• c. Decreased mobilization of stored fats

3
2. Changes of enzyme synthesis

• fatty acid synthesis is induced
• acetyl Co A carboxylase is induced
• adipose lipoprotein lipase is induced

4
IV. Regulation by Allosteric Control

• acetyl CoA carboxylase is activated by
  citrate
• carnitine palmitoyl transferase is inhibited
  by
• malonyl CoA
• increases fructose 2,6 bisphosphate which
  increases
• phosphofructose kinase-1 and decreases
  fructose
• 1,6-bisphosphatase

5
Regulation of Acetyl CoA Carboxylase
See also p780 Lehninger
6
Inhibition of Carnitine Acyl Transferase-I
7
(No Transcript)
8
(No Transcript)