Apocarbonic Anhydrase-Enzymatic Determination of Zinc in Fruit Juices

Authors: Ayşe KARAGÖLGE, Nazan DEMİR, Yaşar DEMİR, İrfan KÜFREVİOĞLU

Abstract: In this study, a new enzymatic method for determining trace amount of zinc was employed on ten different fruit juices. The basis of the enzymatic method is that apocarbonic anhydrase regains its activity in proportion to the Zn^{2+} existing in a solution. Thus, the more activated the enzyme is in the medium, the higher the Zn^{2+} concentration in the solution will be. For this purpose, bovine carbonic anhydrase was purified from erythrocyte hemolisate by affinity chromatography. The Zn^{2+} bound to the enzyme was removed by of the purified enzyme against the solution of pyridine-2-6-dicarboxylic acid. Thus 100\% purified enzyme was obtained. First, the presence of Zn^{2+} in the fruit juices sample was determined by the enzymatic method. Then the content of Zn^{2+} in the same sample was measured by atomic absorption spectroscopy. According to the results obtained, the enzymatic method that we have developed is a variable means of determining.

Keywords: Fruit juices, Zinc determination, Apocarbonic anhydrase.

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