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Pseudomonas aeruginosa acid phosphatase Activation by divalent cations and inhibition by aluminium ion
Author(s) -
Domenech Carlos E.,
Lisa Teresita A.,
Salvano Mario A.,
Garrido Mónica N.
Publication year - 1992
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(92)80108-s
Subject(s) - divalent , chemistry , aluminium , pseudomonas aeruginosa , phosphatase , alkaline phosphatase , acid phosphatase , ion , inorganic chemistry , biochemistry , pseudomonas , enzyme , biology , bacteria , organic chemistry , genetics
In Pseudomonas aeruginosa , the effect of different cations on the acid phosphatase activity was studied in order to acquire more information related to a previously proposed mechanism, involving the coordinated action of this enzyme with phospholipase C. Although the natural substrate of this enzyme is phosphorylcholine, in order to avoid the possible interaction of its positive charge and those of the different cations with the enzyme molecule, the artificial substrate p ‐nitrophenylphosphate was utilized. Kinetic studies of the activation of acid phosphatase (phosphorycholine phosphatase) mediated by divalent cations Mg 2+ , Zn 2+ and Cu 2+ revealed that all these ions bind to the enzyme in a compulsory order (ordered bireactant system). The K m values obtained for p ‐NPP in the presence of Mg 2+ , Zn 2+ and Cu 2+ were 1.4 mM, 1.0 mM and 3.5 mM, respectively. The K A values for the same ions were 1.25 mM, 0.05 mM and 0.03 mM, respectively. The V max obtained in the presence of Cu 2+ was about twofold higher than that obtained in the presence of Mg 2+ or Zn 2+ . The inhibition observed with Al 3+ seems to be a multi‐site inhibition, The K ′ app and n values, from the Hill plot, were about 0.25 mM and 4.0 mM, respectively, which were independent of the metal ion utilized as activator. It is proposed that the acid phosphatase may excert its action under physiological conditions, depending on the availability of either one of these metal ions.