Immobilization and characterization of acid phosphatase from wheat germ (Type I) in agarose gel

Abstract

Acid phosphatase (specific activity 1.82 U/mg) from wheat germ was immobilized by entrapment in agarose gel. Blocks of 5 × 5 mm dimension were used for characterization. The optimum percent immobilization was 75.25% when agarose–enzyme mixture concentration was 1.35%. The soluble and immobilized acid phosphatase exhibited emission maxima at 335 nm, respectively, when excitation wavelength was 280 nm. The intensity of immobilized enzyme was lower than corresponding soluble enzyme. Fourier Transform Infrared spectrum exhibited bands at wave numbers 3282.2 and 1635.9 cm−1 for immobilized enzyme. The optimum pH and temperature for immobilized acid phosphatase were 5.5 and 60 °C, respectively. The Km values for soluble and immobilized acid phosphatase were 0.068 and 0.232 mM, respectively. The Vmax values for soluble and immobilized acid phosphatase were 1.92 and 2.34 µmol/min/mg protein, respectively. The immobilized enzyme retained 48% activity on 56th day when stored at 4 °C. The same enzyme blocks could be reused up to 8 cycles. The method of immobilization reported here is simple and cost effective and will be suitable for further applications.