The Protein Journal

, 27:292

A Dual-Purpose Protein Ligand for Effective Therapy and Sensitive Diagnosis of Anthrax

Authors

  • Momchilo Vuyisich
    • Biosciences Division, Group B-7Los Alamos National Laboratory
  • S. Gnanakaran
    • Theory Division, Group T-10Los Alamos National Laboratory
  • Julie A. Lovchik
    • Center for Infectious Diseases and Immunity, University of New Mexico Health Science CenterUniversity of New Mexico
  • C. Rick Lyons
    • Center for Infectious Diseases and Immunity, University of New Mexico Health Science CenterUniversity of New Mexico
    • Biosciences Division, Group B-7Los Alamos National Laboratory
Article

DOI: 10.1007/s10930-008-9137-0

Cite this article as:
Vuyisich, M., Gnanakaran, S., Lovchik, J.A. et al. Protein J (2008) 27: 292. doi:10.1007/s10930-008-9137-0

Abstract

This article reports the design of a bivalent protein ligand with dual use in therapy and diagnosis of anthrax caused by Bacillus anthracis. The ligand specifically binds to PA and thereby blocks the intracellular delivery of LF and EF toxins that, respectively, cause cell lysis and edema. The ligand is a chimeric scaffold with two PA-binding domains (called VWA) linked to an IgG-Fc frame. Molecular modeling and binding measurements reveal that the VWA-Fc dimer binds to PA with high affinity (K D = 0.2 nM). An in vitro bio-luminescence assay shows that VWA-Fc (at nanomolar concentration) protects mouse macrophages from lysis by PA/LF. In vivo studies demonstrate that VWA-Fc at low doses (∼50  μg/animal) are able to rescue animals from lethal doses of PA/LF and B. anthracis spores. Finally, VWA-Fc is utilized as the capture molecule in the sensitive (down to 30 picomolar) detection of PA using surface plasmon resonance.

Keywords

Anthrax Lethal toxins Bivalent protein chimera Therapy Detection

Abbreviations

CFU

Colony forming units

CMG2

Capillary morphogenesis protein 2

EF

Edema factor

Fc1

Flow cell 1

I.V.

Intravenously

K a

Association rate

K D

Dissociation constant

LF

Lethal factor

MD

Molecular dynamics

MIC

Minimum inhibitory concentration

PA

Protective antigen

RU

Response units

SPR

Surface plasmon resonance

TEM8

Tumor endothelial marker 8

VWA

Von Willebrand factor A

VWA-Fc

Bivalent chimeric PA ligand with Fc fusion

VWA-H6

VWA domain with C-terminal Histidine tag

Copyright information

© Springer Science+Business Media, LLC 2008