Question

To support the mechanism by which an ODN inhibits IN activity, which experiment should be performed?

A) Keep IN concentration constant and measure the initial velocity of the reaction at increasing vDNA concentrations in the presence and absence of the ODN.
B) Keep vDNA concentration constant and measure the initial velocity of the reaction at increasing concentrations of IN in the presence and absence of the ODN.
C) Keep ODN and IN concentration constant and measure initial velocity of the reaction at increasing concentrations of vDNA.
D) Keep IN and vDNA concentrations constant and measure initial velocity of the reaction at increasing concentrations of the ODN.

Answer 1

To support the mechanism by which an ODN inhibits integrase (IN) activity, the recommended experiment is Option A, where IN concentration is constant and the reaction velocity is measured at various vDNA concentrations in the presence and absence of the ODN.

Step-by-step explanation:

To support the mechanism by which an oligodeoxynucleotide (ODN) inhibits integrase (IN) activity, the most appropriate experiment would be Option A. In this scenario, the IN concentration is kept constant while the initial velocity of the reaction is measured at increasing viral DNA (vDNA) concentrations. This approach allows for the characterization of how the presence of the ODN affects the reaction velocity as the substrate concentration changes. This type of experiment is akin to creating a Michaelis-Menten plot, a common method in enzyme kinetics to determine the type and level of inhibition exerted by a molecule on enzyme activity.

Options B, C, and D would each provide different insights but would not be as effective in isolating the effect of ODN on IN. Competitive inhibition can often be identified by examining how changes in substrate concentration influence the initial reaction rate in the presence versus the absence of an inhibitor, since competitive inhibitors typically increase the apparent Km without affecting the Vmax.