Partial purification and characterization of a non-specific acid phosphatase in leaves and root nodules of Phaseolus vulgaris.
Acid phosphatase (ACP) activity in common bean grown with or without 1.5 mM of phosphate has been examined. Leaves and root nodules responded to the absence of an exogenous phosphate source with an increase in ACP activity. Increases in enzyme activity were not associated with the synthesis of new isoforms of the enzyme. We partially purified and characterized the ACPs, which consisted of three proteins, one of leaf and two of nodule. Proteins of leaf migrated at 72 and 51 kDa in SDS-PAGE, whereas that of nodule migrated at 72, 49, 41 and 34 kDa. Enzymes of both organs had a pH optimum of 5.6, and were relatively heat stable. The enzymes exhibit a broad substrate selectivity, with maximal activity obtained with alpha-naphthyl-phosphate, ribulose 1,5-bisphosphate and p-nitrophenyl-phosphate (p-NPP). Potent inhibition by Zn2+, Hg2+, Cu2+, Pb2+, Al3+ and (MoO4)2- was observed.
Departamento de Fisiología Vegetal, Facultad de Ciencias, Universidad de Granada, Campus de Fuentenueva s/n, 18071 Granada, Spain. natejera@ugr.es
Noel A
NA
Tejera García
Marleni
M
Olivera
Carmen
C
Iribarne
Carmen
C
Lluch
D000135:Acid Phosphatase / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism*; D002412:Cations / Q000494:pharmacology; D002413:Cations, Divalent / Q000494:pharmacology; D002852:Chromatography, Ion Exchange; D004791:Enzyme Inhibitors / Q000009:adverse effects; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes / Q000302:isolation & purification / Q000378:metabolism; D007700:Kinetics; D027805:Phaseolus / Q000201:enzymology*; D018515:Plant Leaves / Q000201:enzymology*; D018517:Plant Roots / Q000201:enzymology*
D002412:Cations; D002413:Cations, Divalent; D004791:Enzyme Inhibitors; D007527:Isoenzymes; D000135:Acid Phosphatase