Ths is a HiLyte Fluor labeled HIV protease substrate I, GABA-Ser-Gln-Asn-Tyr-Pro-Ile-Val-Gln-EDANS. The peptide sequence is derived from the native p17/p24 cleavage site on HIV precursor polyprotein Prgag for HIV-1 protease. Cleavage of HIV precursor polyproteins is essential for the maturation of the infectious virus and hence the protease has become a major target for developing anti-AIDS drugs. The peptide substrate is widely used for the continuous assay for HIV protease activity. The QXL/488 pair offers better sensitivity in detection at a higher wavelength with less background interference. (Excitation/Emission = 490 nm/520 nm).