Acetyl-CoA carboxylase is a key regulatory enzyme in fatty acid synthesis. Early studies on the molecular properties of this enzyme purified from avian liver produced the data given in table.
Table: Molecular properties of avian acetyl-CoA carboxylase
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Treatments
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Sedimentation coefficient (S)
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Molecular mass (kDa)
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Catalytic activity (arbitrary units)
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10 mM citrate
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55-59
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4000-8000
|
35
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0.5M NaCl, pH8-9
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13.1
|
410
|
2.5
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a) Explain the results shown in table in terms of the molecular structure of acetyl-CoA carboxylase and comment on their apparent physiological significance.
b) Which cellular compartment would you expect the acetyl-CoA carboxylase activity to have been observed in and why?