SensoLyte™ West Nile Virus Protease Assay Kit – Industry’s First

While West Nile virus (WNV) has had significant outbreaks throughout the world since it was first identified, commercially available assay kits for the detection of WNV protease inhibitors have been non-existent. Until now.

AnaSpec is pleased to introduce the industry’s first commercially available assay kits for the detection of WNV protease NS3 inhibitors – the SensoLyte™ series of WNV Protease Assay Kits.

West Nile virus (WNV), from the family Flaviviridae,1 was first identified in the West Nile district of Uganda in 1937.2 WNV outbreaks have been reported in Israel in the 50’s, France in the 60’s and South Africa in the 70’s.3 In 1999, the first documented WNV infection in the US was reported in New York.4 The main route of human infection is through infected mosquito bites. WNV infection can cause severe neurological disease and fatalities in both human and animal hosts.

SensoLyteTM WNV Protease Assay Kits:
  • Industry's First & Only
  • Fluorogenic
  • Sensitive
  • Homogeneous
  • Ideal for HTS of WNV Protease inhibitors
  • Fast (as short as 30 minutes)

  • WNV contains a single-stranded, positive-sense RNA genome, which encodes three structural proteins (capsid (C), membrane (M), envelope (E)), and seven non-structural proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B, NS5).5, 6 NS3 protease is essential (along with viral-encoded cofactor NS2B) for post-translational processing of a viral polypeptide precursor in infected host cells. This polypeptide provides the structural and functional viral proteins. Inhibition of its processing could represent a potential treatment for viral infections. With no effective vaccine or antiviral drug to protect against WNV infection,7 this protease represents a potentially key target for developing anti-WNV drugs.8, 9

    The SensoLyte™ AMC West Nile Virus Protease Assay Kit provides a convenient, homogeneous assay for high throughput screening of West Nile Virus protease NS3 inhibitors. Utilizing a fluorogenic peptide, it provides continuous quantification of protease activity.10 The peptide generates the AMC (7-amino-4-methylcoumarin) fluorophore upon NS3 protease cleavage. AMC has bright blue fluorescence that can be detected with excitation at 354 nm and emission at 442 nm.

    SensolyteTM West Nile Virus Protease Assay Kits:
    SensoLyteTM 570 West Nile Virus Protease Assay Kit

    3 Step Process (96-well format):

    1. Prepare working solutions:
    a) Fluorogenic substrate (Component A)
    b) WNV protease (not provided)
    c) WNV inhibitor (Component D)
    2. Set up enzymatic reaction (protease+ inhibitor, controls), 37C for 10 min.

    3. Add diluted fluorogenic substrate, mix and start reading fluorescence signal (kinetic or end-point).

    Figure 1. Inhibition of WNV by protease inhibitor, undeca-D-Arg-NH2.


    1. Hayes, CG. Ann. N.Y. Acad. Sci 951, 25 (2001)
    2. Smithburn, KC, et al. Am J Trop Med. 20, 471 (1940).
    3. Internet., accessed April 13, 2007. 4. Klee, AL. et al. Emerg Infect Dis. 10, 1405 (2004).
    5. Brinton, MA.Annu. Rev Microbiol. 56, 371 (2002).
    6. Lanciotti, RS. et al., Science 286, 2333 (1999).
    7. Van Der Meulen, KM et al., Arch. Virol. 150, 637 (2005).
    8. Mueller, al., Int. J Biochem. Cell Biol. 39(3), 606 (2007).
    9. Shiryaev, SA. et al., Biochem. J 393, 503 (2006).
    10. Chappell, KJ. et al., J Biol. Chem. 281, 38448 (2006).