Direction: HMGCoA reductase that binds HMGCoA, is the major rate limiting step in the cholesterol biosynthetic pathway. Several inhibitors of this enzyme are used as potential drugs. The assay of the enzyme is based on labeling the enzyme with radiolabeled HMGCoA and counting (cpm) the labeled enzyme substrate complex in the presence (test) and in the absence (control) of the inhibitor. A bland is set up that contains no enzyme.
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An inhibitor is considered active if it causes more than 65% inhibition. The. cpm Values respectively of control, test and blank samples for inhibitors W, X, Y and Z are given below. State which of the inhibitors is active.
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- X – 8000, 4000 and 100
- W – 7000, 1400 and 135
- Y – 7500, 5000 and 90
- Z – 7200, 2800 and 200
Correct Option: B
For each a, b, c, and d options respectively.
The value of % inhibition is For,
| a = | = 50.6 % | |
| 8000 - 100 |
| b = | = 81.5 % | |
| 7000 - 135 |
| c = | = 33.7 % | |
| 7500 - 90 |
| d = | = 62.86 % | |
| 7200 - 200 |
