PURIFICATION AND IMMUNOLOCALIZATION OF THE PEROXISOMAL 3-OXOACYL-COA THIOLASE FROM SACCHAROMYCES-CEREVISIAE

A molecular understanding of peroxisome biogenesis depends upon the an alysis of peroxisomal proteins. Here we describe the isolation of the 3-oxoacyl-CoA thiolase of the peroxisomal beta-oxidation system from S accharomyces cerevisiae as a dimer of identical subunits, each with a molecular mass of 45 kDa. Monospecific polyclonal antibodies were rais ed against the purified enzyme, and its peroxisomal origin was demonst rated by immunoblotting of subcellular fractions as well as by immunog old labelling. We also show that these antibodies could be suitable fo r an immunofluorescence microscopy screening of yeast mutants affected in peroxisome assembly.