NS2b(cyt domain)-NS3(Protease domain S7) (A1394-L1440/GGGGSGGGG/A1476-K1660)
NS2b(cyt domain)-NS3(Protease domain S7) (A1394-L1440/GGGGSGGGG/A1476-K1660)
Our recombinant Dengue Virus NS2b-NS3 protease complex is of high, crystallography-grade quality and is well suited for researchers pursuing the development of antiviral therapeutics against Dengue, Zika, West Nile, and Yellow Fever viruses.
The complex consists of the serine protease NS3 and its cofactor NS2B and is responsible for processing the viral polyprotein, a function essential for viral replication and the production of new viral particles. Consequently, it represents a validated and attractive target for the development of inhibitors, for example, those targeting the active site of the NS2B-NS3 complex.
The construct design was was based on published structures in the Protein Data Bank (PDB ID: 4M9K): The construct includes the cytoplasmic cofactor region of NS2B spanning residues A1394-L1440, connected via a GGGG-S-GGGG linker to the NS3 protease domain which spans residues A1476-K1660. The NS2B region contains four mutations (T1402A, K1405R, D1407E, D1408E). Additionally, the construct contains an N-terminal overhang of six amino acids (GSHMLE) with the initial glycine remaining from the TEV cleavage site.
Structure and function
The N-terminal residues of the NS3 protease form a chymotrypsin-like serine protease domain which mediates polyprotein cleavage to release individual viral proteins. It requires NS2B as a cofactor for proper folding and enzymatic activity. The N-terminal region of the NS2B cofactor has been shown to facilitate protease folding by contributing a β-strand to the N-terminal β-sheet of the NS3 protease. The C-terminal region of NS2B is required for protease activity, as it completes the substrate-binding pocket of the NS3 protease domain when adopting the "closed conformation" NS2B can adopt distinct conformations and dynamically interconverts between an open (inactive) and closed (active) state.
Ns2B-NS3 as important drug target
Disruption of viral polyprotein processing prevents dengue virus replication and propagation. Consequently, the NS3 protease domain represents an attractive target for drug development. Antiviral therapeutic strategies have so far focused on both orthosteric inhibitors (mimicking the polyprotein cleavage site) and allosteric inhibitors that prevent the transition to the active "closed" state.
References:
Lee, Wen Hao Kenneth. (2021) . Dengue virus protease activity modulated by dynamics of protease cofactor. Biophys J. doi: https://doi.org/10.1016/j.bpj.2021.04.015.
Phoo, Wint Wint. (2020). Crystal structures of full length DENV4 NS2B-NS3 reveal the dynamic interaction between NS2B and NS3, Antiviral Research, https://doi.org/10.1016/j.antiviral.2020.104900.
quality assurance
QualityPlus stands for exceptional protein quality in structural biology applications. While many suppliers offer crystallographic-grade proteins, we chose to go a step further.Based on repeated customer feedback, our proteins are consistently described as exceptionally pure—often surpassing what is typically available on the market. Additionally, QualityPlus means a plus in transparently communicated quality control. Instead of relying solely on SDS-PAGE, we ensure strict batch-to-batch consistency through comprehensive QC, including assessments of monodispersity and thermostability, SEC polishing, and verified purity exceeding 95%.
All our proteins are for scientific usage only!
Protein Characteristica
EEQTLGGGGSGGGGAGVLWDVPSPPPVGKAELEDGAYRIKQKGILGYS
QIGAGVYKEGTFHTMWHVTRGAVLMHKGKRIEPSWADVKKDLISYGGG
WKLEGEWKEGEEVQVLALEPGKNPRAVQTKPGLFKTNTGTIGAVSLDF
SPGTSGSPIVDKKGKVVGLYGNGVVTRSGAYVSAIANTEKSIEDNPEI
EDDIFRK