Pseudomonas aeruginosa acid phosphatase Activation by divalent cations and inhibition by aluminium ion

FEBS Letters

Lisa, Teresita A.¹  Domenech, Carlos E.¹  Salvano, Mario A.¹  Garrido, Mónica N.¹ 

[1] Quimica Biológica, Departamento de Biologia Molecular, Facultad de Ciencias Exactas, Fisico-Químicas y Naturales, Universidad Nacional de Rio Cuarto, 5800 Rio Cuarto, Córdoba, Argentina

关键词: Acid phosphatase;    Phosphorylcholine phosphatase;    Pseudononias aeruginosa;    Choline;    Infection;    p-NPP;    p-nitrophenylphosphate;   

DOI  :  10.1016/0014-5793(92)80108-S

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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 Mg²⁺, Zn²⁺ and Cu²⁺ 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 Mg²⁺, Zn²⁺ and Cu²⁺ 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 Cu²⁺ was about twofold higher than that obtained in the presence of Mg²⁺ or Zn²⁺. The inhibition observed with Al³⁺ 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.

【 授权许可】

Unknown