Characterization of a Novel Acid Phosphatase from Embryonic Axes of Kidney Bean Exhibiting Vanadate-dependent Chloroperoxidase Activity

Abstract

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.

Comparative Analysis of PvPAP Gene Family and Their Functions in Response to Phosphorus Deficiency in Common Bean

“…Since constitutive and Pi-starvation induced expression patterns were separately found for PvPAP1 and PvPAP3 in roots of two bean genotypes (Figure 4), it was suggested that PvPAP1 might function under normal conditions, while PvPAP3 might be regulated to function under Pi-starvation conditions. It has been suggested that PvPAP1 and PvPAP2 might be involved in seed germination of bean because transcripts of PvPAP1 and PvPAP2 were separately increased in embryonic axis and cotyledons during seed germination [37], [38]. Therefore, it might be possible that PvPAP1 might exhibit multiple functions in bean except to participate in extracellular dNTP utilization.…”

Isozymes of plant hexokinase: Occurrence, properties and functions

“…However, sequence homology or biochemical evidence for the presence of these enzymes in plants is lacking (Claeyssen and Rivoal, unpublished observations). In vitro phosphatase activities with G1P and G6P have been reported, but seemed to be due to low substrate specificity of acid phosphatases (Duff et al, 1989;Bozzo et al, 2004;Yoneyama et al, 2004). Whether these activities have physiological relevance to Glc/Glc-P cycling remains to be established.…”

Gene expression profiles in testis of developing male Xenopus laevis damaged by chronic exposure of atrazine

“…It has been shown that acps are involved in the immune, reproductive and digestive systems, and apoptosis. (Sun et al, 2006;Bozzo et al, 2002;Yoneyama et al, 2004). A study on amphioxus has demonstrated that ACPs were presented in sperm with roles in proliferation and maturation of sperm (Sun et al, 2006).…”