Fluoride Quantitation in Aqueous Solution by Agarose Immobilized Pumpkin Urease

Soluble as well as agarose immobilized pumpkin urease was utilized for easy and rapid detection and quantitation of fluoride in aqueous solution. Pumpkin urease was immobilized in 1.5 % agarose leading to 74.2 % immobilization. Inhibition by both soluble and agarose immobilized enzyme revealed a clear dependence on concentration and time. In order to inhibit the activity completely in soluble enzyme, 45 mM fluoride was required while agarose immobilized enzyme required almost double the concentration of the inhibitor i.e., 80 mM. The inhibition caused by fluoride was noncompetitive with Ki value of 3.9 and 2.3 mM. The significance of the observations is discussed.