1> How many microliters of the 1.0 mM NAD+ solution would you need to use, to make 3.0 mls of a 50 µM NAD+ solution?
2> Many recombinant proteins are engineered to have a poly-histidine tag (His-tag), a stretch of at least six histidine (His) residues, at their N- or C-terminus to aid in their purification via Nickel-NTA (Ni-NTA) affinity chromatography. In this system, the supporting matrix contains nickel, which has a very high affinity for the histidine side chain at pH 7.0-8.0. Based on this information, which of the following compounds can be introduced to the system as a soluble ligand to compete with the His-tagged protein for binding to the Ni-NTA column and cause it to elute from the column? Note to answer this question you need to look up the chemical structures of the proposed ligands and compare them to the structure of the moiety recognized by the matrix used in this affinity chromatography set-up.
A) ATP
B) Imidazole
C) NADH
D) Coomassie blue G-250