Inhibition of ricin A-chain (RTA) catalytic activity by a viral genome-linked protein (VPg).

ABSTRACT: Ricin is a plant derived protein toxin produced by the castor bean plant (Ricinus communis). The Centers for Disease Control (CDC) classifies ricin as a Category B biological agent. Currently, there is neither an effective vaccine that can be used to protect against ricin exposure nor a therapeutic to reverse the effects once exposed. Here we quantitatively characterize interactions between catalytic ricin A-chain (RTA) and a viral genome-linked protein (VPg) from turnip mosaic virus (TuMV). VPg and its N-terminal truncated variant, VPg1-110, bind to RTA and abolish ricin's catalytic depurination of 28S rRNA in vitro and in a cell-free rabbit reticulocyte translational system. RTA and VPg bind in a 1 to 1 stoichiometric ratio, and their binding affinity increases ten-fold as temperature el

SUBMITTER: Aitbakieva VR 

PROVIDER: S-EPMC7219317 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature