They also crossed technological barriers impeding development of drugs for several other deadly conditions. Those barriers stemmed from the difficulty in developing drugs to inhibit the action of enzymes known as proteases.
Proteases act as molecular scissors.
They cut proteins, the molecules that perform a multitude of useful functions in the body. HIV-1 protease cleaves apart viral proteins, allowing them to assemble into functional virus particles. Protease inhibition research is not new. It's still hard, however, to find those potent, selective inhibitors and give them the physical properties, such as solubility and stability, that will allow them to become drugs. Inhibiting Clots Clots are often a problem during surgery, especially knee and hip replacements, when the blood supply to the limb involved is often shut off or diverted to prevent hemorrhaging.