How do I know the Fradditive™ will bind to my protein?
You don't! But, you do know that ligands can be the deciding factor in protein expression, purification and crystallization. These Fradditives™ were selected to maximize probability of binding to a protein target. Very small simple molecules that are primarily fragments of natural products.
What if the Fradditive™ binds at the active site? How will I obtain co-crystal structures?
Because of their small simple structure, it is likely that the compound will not bind tightly to the active site. For soaking ligands: soaking out the Fradditive™ and soaking in ligands has been shown to be very reliable. If the Fradditive™ does bind tightly, congratulations, you have a possible starting point for drug discovery. While soaking out tightly bound ligands can be a challenge, it is possible through mass action. You may also try co-crystallization.
What if the Fradditive™ alters my protein's activity?
This is possible of course. The Fradditive™ may bind at an allosteric site and be functionally relevant which is critical information for your drug discovery program. You may soak the Fradditive™ out and screen for additional allosteric modifiers.