Question

1) Viral DNA polymerase is inhibited by an anti-viral drug. Why do anti-viral drugs target viral DNA polymerase?
2) Phosphate groups of DNA nucleotides=protanated (Had H+ ions added to them) So electrophoresis failed to seperate fragments. Explain why

Answer 1

1) the drugs target the mode of replication of the virus, they do this because it's a way to stop it from spreading (would be a straight forward explanation). They do these by mimicking some chemical intermediate or substrate. For example this drug http://en.wikipedia.org/wiki/Acyclovir looks like a nucleotide and is incorporated into the viral DNA and inhibits the Pol.

2) electrophoretic mobility (in an electric field) is dependent on the charge (negative) on the DNA, if you protonate the O's on the phosphates the DNA molecule is then neutral and wont migrate in the electric field (although at the pH necessary to fully protonate the phosphates you would inevitably protonate the nucleic bases and form positive charges, and/or break them down)

Answer 2

1) As viral DNA polymerase is responsible for the replication of virus - hence anti viral drug acts upon the enzyme Viral DNA polymerase to stop the replication capacity of the virus and reduce its dangerous effect.

2) @aaronq is correct.

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