CHARACTERIZATION OF A MONOCLONAL-ANTIBODY PREPARED AGAINST PLANT ACTIN

Anti-actin monoclonal antibodies were prepared using phalloidin-stabil ized actin that was purified from pea roots by DNase I affinity chroma tography. One monoclonal antibody, designated mAb3H11, bound plant act in in preliminary screenings and was further analyzed. Immunoblot anal ysis showed that this antibody had a high affinity for plant actin in crude and purified preparations but a low affinity for rabbit muscle a ctin. In immunoblots of plant extracts separated on two-dimensional ge ls it appeared to bind all actin isoforms recognized by the JLA20 anti -chicken actin antibody. Using immunofluorescent cytochemistry, the an tibody was used to observe actin filaments in aldehyde-fixed and metha nol-treated tobacco protoplasts. These results indicate that mAb3H11 s hould be a useful reagent for the study of plant actins. (C) 1994 Wile y-Liss, Inc.