Exercise 4
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 3.
Table 3. Molecular properties of avian acetyl-CoA carboxylase
Treatments |
Sedimentation coefficient (S) |
Molecular mass (kDa) |
Catalytic activity (arbitrary units) |
10 mM citrate |
55-59 |
4000-8000 |
35 |
0.5M NaCl, pH8-9 |
13.1 |
410 |
2.5 |
l)
Explain the results shown in table 3 in terms of the molecular structure of acetyl-CoA carboxylase and comment on their apparent physiological significance.
l) Which cellular compartment would you expect the acetyl-CoA carboxylase activity to have been observed in and why?