Question

How does the Near Attack Conformation (NAC) contribute to enzyme function? How can an enzyme put a substrate into an energetically unfavorable conformation? How does modern drug design utilize NAC? Please go into detail, provide examples, and use diagrams to help illustrate your explanation. Especially use diagrams please.  

Edit: NAC is "Near Attack Conformation"

Answer 1

substrate may adopt near-attack conformations (NAC), which more approximate the bound transition state, and it is the binding of the NAC to the enzyme, not lowering the activation energy, that contributes to the enzyme catalyzed rate enhancement.

Many energetically unfavorable reactions in cells are coupled to the hydrolysis of the molecule ATP. The breakdown of ATP to ADP is a highly energetically favorable reaction that releases energy. This energy is then used to carry out the unfavorable reaction.

The two most common techniques for determining three-dimensional structures of protein targets for drugs are X-ray crystallography and nuclear magnetic resonance spectroscopy.