BK Polyomavirus (BKPyV) Research Reagents — Antibodies & Recombinant Proteins

Major Capsid Protein VP1 — Neutralization & Therapeutic Target
VP1 pentamers form the icosahedral capsid (72 pentamers per virion) and mediate receptor binding via sialylated gangliosides (GT1b, GD1b). VP1 is the sole target for neutralizing antibodies and the basis for all BKPyV therapeutic antibodies in clinical development. VP1 serotypes (genotypes I–IV) determine antibody specificity and cross-neutralization breadth. abinScience provides the deepest anti-VP1 antibody panel available:
• Biosimilar-grade reference antibody: Traxivitug (VK698016) — sequence-identical to the clinical-stage anti-BKPyV VP1 therapeutic antibody for PK/ADA/bioactivity reference
• Recombinant anti-VP1 neutralizing antibodies: MTX-005 (VK452013), 336F07 (VK452023), 319C07 (VK452033), P8D11 (VK452043), MAU868 (VK452053), and SAA3067 (VK452063)
• Recombinant VP1 proteins: C-His (VK452011) and N-MBP&C-His (VK698032) — MBP-tagged version enhances VP1 solubility for pentamer assembly studies

Large T Antigen (LTag)
LTag is the multifunctional regulatory protein that drives viral DNA replication (origin binding, helicase activity) and cell cycle dysregulation (pRb/p53 inactivation). LTag-mediated oncogenic transformation is the basis for BKPyV-associated urothelial carcinoma research. Available: recombinant LTag protein N-His (VK798012).

Agnoprotein — Viral Assembly & Egress
Agnoprotein is a small (~8 kDa) late-expressed protein essential for viral assembly, nuclear egress, and virion release. Agnoprotein is a unique feature of BKPyV and JCPyV (not present in SV40 or MCPyV) and a potential antiviral target. Available in three formats: N-His-SUMO (VK523012), N-His (VK523022), and N-His-SUMO variant (VK523032).

What is Traxivitug and how is it used?
Traxivitug (VK698016) is a research-grade antibody with a sequence identical to the clinical-stage anti-BKPyV VP1 therapeutic antibody being developed for PVAN prevention in kidney transplant recipients. It is intended for use as a positive control in neutralization assays, PK/ADA assay reference standard, and bioactivity benchmark in BKPyV therapeutic development programs.

Which VP1 protein format is best for serology ELISA?
VP1 C-His (VK452011) is recommended for direct ELISA plate coating. VP1 naturally assembles into pentamers and virus-like particles (VLPs) — conformational epitopes on assembled VP1 are the primary targets for neutralizing antibodies. The MBP-tagged VP1 (VK698032) may enhance solubility for applications requiring monomeric VP1.

Do your anti-VP1 antibodies cross-react with JC polyomavirus (JCPyV)?
BKPyV and JCPyV VP1 share ~78% amino acid identity. Some broadly reactive clones (e.g., P8D11) may cross-react, while genotype-specific clones may not. Contact us for clone-specific cross-reactivity data with JCPyV and SV40.

Why are there 6 different anti-VP1 antibody clones?
BKPyV VP1 has four major genotypes (I–IV) with variable loop regions that affect antibody binding. Having multiple clones targeting different VP1 epitopes enables: (1) identification of broadly neutralizing antibodies covering all genotypes; (2) epitope competition/binning for therapeutic cocktail design; (3) matched pair selection for VP1-capture sandwich ELISA development.

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