Purification of a phi-type glutathione S-transferase from pumpkin flowers, and molecular cloning of its cDNA.
A major species of glutathione S-transferase (GST), Pugf, was highly purified from pumpkin flowers. Two-dimensional electrophoresis of the purified enzyme gave two adjacent protein spots. The specific activity of the purified enzyme was 2.4 micromol min(-1) mg(-1) protein for 1-chloro-2,4-dinitrobenzene. This value is one to two orders of magnitude lower than that of pumpkin tau-type GSTs. The expression pattern of Pugf in healthy pumpkin plants and responses to various stresses were examined by western blotting. Pugf was found in high concentrations in petioles, stems, and roots as well as flowers, and was more abundant in expanding young organs than in fully expanded mature organs. Dehydration caused a slight increase in its concentration, but high and low temperatures, salty stress, and 2,4-dichlorophenoxyacetic acid seemed to have no effects. A cDNA encoding Pugf was cloned and sequenced. Sequence comparison with other plant GSTs suggested that it should be classified as a phi-type GST.
Hossain
Mohammad Zakir
MZ
Department of Plant Sciences, Faculty of Agriculture, Kagawa University, Miki-cho, Kita-gun, Kagawa 761-0795, Japan.
Fujita
Masayuki
M
D015084:2,4-Dichlorophenoxyacetic Acid / Q000633:toxicity; D000917:Antibody Formation; D000918:Antibody Specificity; D015153:Blotting, Western; D002848:Chromatography, DEAE-Cellulose; D003001:Cloning, Molecular; D003429:Cross Reactions; D028464:Cucurbita / Q000201:enzymology*; D018076:DNA, Complementary / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D035264:Flowers / Q000201:enzymology*; D005982:Glutathione Transferase / Q000235:genetics / Q000302:isolation & purification*; D006540:Herbicides / Q000633:toxicity; D010940:Plant Proteins / Q000302:isolation & purification
D018076:DNA, Complementary; D006540:Herbicides; D010940:Plant Proteins; D015084:2,4-Dichlorophenoxyacetic Acid; D005982:Glutathione Transferase