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At present, mineral substances that the human body receives from foodstuffs and water contain seven main macroelements: sodium, potassium, magnesium, calcium, phosphorus, chlorine, and sulfur. An additional 15 essential microelements, apart from macroelements, are necessary for the human body. Worthy of mention are iron, a component of hemoglobin and tissue cytochromes; cobalt, a component of cyanocobalamin (vitamin B 12 ); copper, a component of cytochrome oxidase; zinc, a factor in the promoting effect of insulin on the permeability of cell membranes to glucose; molybdenum, a component of xanthine oxidase; manganese, an activator of some enzymatic systems; and others [1]. In the majority of cases, the above microelements enter into the composition of enzymes, hormones, and vitamins and act as catalysts of enzymatic processes [2].A deficiency or excess of macro-and microelements results in serious disruptions of the normal function of the human body; therefore, the correct estimation of their concentrations in biological systems and the control over their concentrations in living organisms is an important task of analytical chemistry and medicine.The use of enzymes of different classes is promising for the diagnosis of a deficiency of macro-and microelements. The following enzymes have been successfully used in chemical analysis: peroxidase from horseradish roots for determining trace amounts of iron(III) [3] and toxic mercury(II) [4]; alcohol dehydrogenase (ADH) from baker's yeast and pyruvate oxidase for determining zinc [5,6], polyphenol oxidase for determining copper(II) [7,8] and others.In this review, we consider the possibilities of using alkaline phosphatases from different sources for determining metal ions; describe enzymatic procedures for their determination; discuss the approaches to the intentional improvement of the sensitivity and selectivity of determining metal ions; and outline the prospects for the use of alkaline phosphatases of different origin in chemical analysis for determining metal ions in different samples, in particular, in biological samples.It should be noted that the data published over the last thirty years on the effect of metal ions on the catalytic activity of alkaline phosphatases of different origins have not been systematized before. Only the monographs by Boyer [9], Coleman and Gettins [10], Freder [11], and Spiro [12] are worth mentioning. These monographs cover the data published up to 1971 on the sources of alkaline phosphatases, the kinetics and mechanism of their action, thermal stability, and main inhibitors and activators, and the authors systematized them. Methods for determining metal ions using alkaline phosphatases were not discussed in these monographs, which makes this review valid and reasonable.General information about alkaline phosphatases. Alkaline phosphatases (EC 3.1.3.1) belong to the class of hydrolases and catalyze the alkaline hydrolysis of a great number of different phosphoric acid esters; because of this, they are nonspecific enzymes [11]. The sp...

Enzymatic methods of analysis have long been successfully used for determining transition metal ions [Cu(II), Zn(II), Ni(II), and Fe(III)] and heavy metal ions [Hg(II), Cd(II), Pb(II), and Bi(III)] in various water, soil, food, and biological fluid (blood and urine) samples [1][2][3]. As a rule, the inhibiting or activating effects of the above metals on the catalytic activity of native or immobilized enzymes from various classes (usually, oxidoreductases and hydrolases) have been used for this purpose. Enzymatic procedures for determining cofactor metal ions, which enter into the active centers of enzymes and are responsible for their high catalytic activity, exhibited the highest sensitivity and selectivity. These procedures are based on the reactivation of apoenzymes. Procedures for determining Fe(III) with peroxidase [4]; for determining Cu(II) with polyphenol oxidase [5]; and for determining Zn(II) with aminopeptidase [6], alcohol dehydrogenase [7], carboanhydrase [8], and alkaline phosphatase [9][10][11] are well known. A target-oriented change in the sensitivity and selectivity of enzymatic procedures for determining transition metals and heavy metals became possible because of the use of the combined action of two effectors (a metal ion and an organic compound) [12], various analytical signals (reaction rate and the duration of an induction period) [1], various buffer solutions [13], and enzymes from the same class but isolated from different sources [7,12,14].Enzymes have been used very rarely for determining magnesium and alkaline earth metals, although magnesium is a constituent of alkaline phosphatases and ATPases (it is responsible for the high stability of enzymes in storage and regulates (modulates) the catalytic activity of biocatalysts), whereas calcium is a constituent of peroxidases, α -amylases, and phytases (it stabilizes their structures).An analysis of data published in the last decade demonstrated that only a few procedures for the enzymatic determination of the above metals are known. Thus, for example, a highly sensitive procedure was developed for determining magnesium (2.4-2400 µ g/mL); it is based on the activation of firefly luciferase immobilized on BrCN-activated Sepharose [15]. Firefly luciferase catalyses the bioluminescence reaction of luciferin conversion into oxyluciferin in the presence of adenosinetriphosphoric acid and magnesium. This procedure is characterized by high accuracy; however, its wide use in the actual practice of chemical analysis is restricted by time-consuming and laborintensive enzyme preparation and immobilization, as well as by the use of a luminescence technique for monitoring the rate of the indicator process. In the determination of Mg(II) at a level of the determination limit, Ca(II), Sr(II), and Ba(II) in 200-and 400-fold amounts, respectively, caused no interference.A procedure for determining magnesium by its activating effect on the catalytic activity of alkaline phosphatase from chicken intestine in the hydrolysis reaction of p-nitrophenyl phospha...