Soluble and microsomal glutathione s transferase activities in pea seedlings pisum sativum cultivar alaska
Diesperger, H.; Sandermann, H.Jr
Planta (Heidelberg) 146(5): 643-648
1979
ISSN/ISBN: 0032-0935
Accession: 006436242
Epicotyl and primary leaves of pea seedlings (P. sativum L., cv. Alaska) contained soluble and microsomal enzymes catalyzing the addition of glutathione to the olefinic double bond of cinnamic acid. Glutathione S-cinnamoyl transfer was also obtained with enzyme preparations from potato slices and cell suspension cultures of parsley and soybean. The pea transferases had pH-optima between pH 7.4 and 7.8 Km-values were 0.1-0.4 mM and 1-4 mM for cinnamic acid and glutathione, respectively. V-values were between 2-15 nmol mg-1 protein .times. min. Chromatography on Sephacryl S-200 indicated that the soluble pea glutathione S-cinnamoyl transferase activity existed in MW forms of 37,000, 75,000 and 150,000. The glutathione-dependent cleavage of the herbicide fluorodifen was catalyzed by a different soluble enzyme activity which eluted in MW positions of 47,000 and/or 82,000. The microsomal fraction from pea primary leaves also catalyzed the conjugation of the carcinogen benzo[a]pyrene with glutathione.