Characterization of a monoclonal antibody prepared against plant actin

Abstract
Anti‐actin monoclonal antibodies were prepared using phalloidin‐stabilized actin that was purified from pea roots by DNase I affinity chromatography. One monoclonal antibody, designated mAb3H11, bound plant actin in preliminary screenings and was further analyzed. Immunoblot analysis showed that this antibody had a high affinity for plant actin in crude and purified preparations but a low affinity for rabbit muscle actin. In immunoblots of plant extracts separated on two‐dimensional gels it appeared to bind all actin isoforms recognized by the JLA20 anti‐chicken actin antibody. Using immunofluorescent cytochemistry, the antibody was used to observe actin filaments in aldehyde‐fixed and methanol‐treated tobacco protoplasts. These results indicate that mAb3H11 should be a useful reagent for the study of plant actins.