HIV protease acts as new virus particles are budding off a cell membrane. Protease Inhibitor A drug that binds to and blocks HIV protease from working, thus preventing the production of new functional viral particles. Protein Large molecules made up of long sequences of amino acids. Some hormones and all enzymes and cellular structural components are proteins. Resistance Reduction in an organism's sensitivity to a particular drug.
Resistance is thought to result mainly from a genetic mutation.
In HIV, such mutations can change the structure of viral enzymes and proteins so that an antiviral drug can no longer bind with them. Resistance detected by searching a pathogen's genetic makeup for mutations believed to confer lower susceptibility is called genotypic resistance. Resistance found by successfully growing laboratory cultures of the pathogen in the presence of a drug is called phenotypic resistance. A single-stranded molecule composed of nucleotide sequences. In cells, RNA transmits the code from the DNA-based genes that instruct the cells' chemical machinery to produce structural proteins and enzymes.