Characterization of a novel acid phosphatase from embryonic axes of kidney bean exhibiting vanadate-dependent chloroperoxidase activity.
A novel colorless acid phosphatase (KeACP), which was distinct from the kidney bean purple acid phosphatase, was purified to apparent homogeneity and cloned from embryonic axes of kidney bean (Phaseolus vulgaris L. Ohfuku) during germination. When orthovanadate (VO(4)(-3)) is added to the apo form of the enzyme, KeACP uniquely exhibits the chloroperoxidase activity with loss of phosphatase activity. This is the first demonstration that KeACP is a vanadate-dependent chloroperoxidase in plants to be characterized and suggests that KeACP may play a role in modifying a wide variety of chlorinated compounds that are present in higher plants. The enzyme is a dimer that presents three forms made up of the combination of the dominant 56-kDa and the minor 45-kDa subunits, and both subunits contain carbohydrate. The full-length cDNA of the KeACP gene is 1641 nucleotides, and this sequence is predicted to encode a protein having 457 amino acid residues (52,865 Da), including a signal peptide. The complete nucleotide sequence of the genomic DNA (3228 bp) of KeACP consists of seven exons and six introns. Northern blot analysis demonstrated that the KeACP gene was expressed specifically in embryonic axes of the kidney bean, and its expression coincided with elongation of the embryonic axis during germination.
Yoneyama
Tohru
T
Department of Food Science and Technology, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri 099-2493, Japan.
Shiozawa
Masae
M
Nakamura
Masao
M
Suzuki
Tomonori
T
Sagane
Yoshimasa
Y
Katoh
Yoshinobu
Y
Watanabe
Toshihiro
T
Ohyama
Tohru
T
D000135:Acid Phosphatase / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D002711:Chloride Peroxidase / Q000378:metabolism*; D002850:Chromatography, Gel; D017931:DNA Primers; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D027805:Phaseolus / Q000196:embryology / Q000201:enzymology*; D012639:Seeds / Q000201:enzymology*; D013379:Substrate Specificity; D014638:Vanadates / Q000494:pharmacology*
D017931:DNA Primers; D014638:Vanadates; D002711:Chloride Peroxidase; D000135:Acid Phosphatase