CloneID: ZKA64
Antigen Long Description: mAb ZKA64 was selected from EBV-immortalized memory B cells derived from ZIKV-infected, DENV-naïve human donors based on its ability to bind Zika virus (ZIKV) E protein and to neutralize ZIKV infection.
Buffer Composition: PBS only.
Chimeric Use Statement: This chimeric mouse antibody was made using the variable domain sequences of the original Human IgG1 format, for improved compatibility with existing reagents, assays and techniques.
Uniprot Accession No.: Q91KX7
Specificity Statement: ZKA64 binds specifically to the EDIII domain of the ZIKV envelope (E) protein. It does not cross-react with DENV E protein. Flavivirus E proteins mediate fusion, with EDIII being specifically invovled in binding to cellular receptors. The ZIKV E protein has homolgy to that in Dengue virus (DENV) as well as other flaviviruses such as yellow fever and west nile. ZIKV is a flavivirus that can be transmitted sexually, by the Aedes mosquito vector, or vertically to a developing fetus. Most cases of ZIKV infection are asymptomatic or manifest in mild symptoms, but in some cases ZIKV infection can result in Guillain-Barré Syndrome or congenital birth defects in developing fetuses.
Application Notes (Clone): ZKA64 is able to neutralize ZIKV with an IC50 of ~93 ng/ml. This antibody also enhances ZIKV infection in non-permissive K562 cells at a broad range of concentrations (but not above 1 μg/ml). The LALA format of ZKA64 (an Fc mutant variant that does not bind to Fc gamma receptors and only weakly to complement - similar to Absolute Antibody's Fc Silent™ format) is able to block enhancement of ZIKV infection by ZIKV-immune plasma from convalescent patients in K652 cell by the ADE (antibody-dependent enhancement) effect - this is due to the capacity of ZKA64 to out-compete serum enhancing antibodies and to neutralize ZIKV once internalized into endosomes. ZKA64-LALA is able to completely protect A129 mice from death and body weight-loss when administered with a lethal dose of ZIKV. Neutralization of ZIKV infection can be measured using a micro-neutralization FC-based assay, and binding/specificity to E protein can be studied by ELISA. Paul et al. (2016, PMID: 28090318) used the mouse IgG2a version of this antibody (Ab00779-2.0) positive control for antibody-mediated virus neutralization.