In: Chemistry
Kinetic Properties of a Key Enzyme of Prostaglandin Synthesis
Prostaglandins are derived from the 20-carbon fatty acid arachidonic acid in a reaction catalyzed by the enzyme prostaglandin endoperoxide synthase. The enzyme converts arachidonic acid to PGG2, the immediate precursor for many prostaglandins. The table below show the result of enzyme activity with or without an inhibitor, ibuprofen.
You need first to determine the Vmax and Km, with and without the inhibitor, and then determine which type of inhibitor Ibuprofen is. The data given here makes it does not afford convenient assessment of Vmax and Km by conventional Michaelis Menten graph (since saturation is not reached under the experimental conditions). Therefore, a Lineweaver-Burke analysis is required. Fill the table with the reciprocal values. The results then are to be drawn as a non-logarithmic graph (next page).
[S], mM (arachidonic acid) |
1/[S] |
Vo, mM/min (rate of PGG2 formation) |
1/Vo |
Vo(Ib), mM/min (with ibuprofen) |
1/Vo(Ib) |
0.5 |
23.5 |
16.67 |
|||
1.0 |
32.2 |
25.25 |
|||
1.5 |
36.9 |
30.49 |
|||
2.5 |
41.8 |
37.04 |
|||
3.5 |
44.0 |
38.91 |
Please show the equation on how to find the 1/[s], the 1/Vo and the 1/Vo[Ib] in the chart. Thank you