Purification and Characterization of Acid Phosphatase from the Egg of the Lady Beetle, Harmonia axyridis (Coccinellidae: Coleoptera)

Authors

  • Jun Hyuk LEE,

    1. Department of Applied Biology, College of Agriculture and Life Sciences, Kangwon National University, Chunchon 200- 701, Kangwon-Do, Korea
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  • Yong Chul PARK

    Corresponding author
    1. Department of Applied Biology, College of Agriculture and Life Sciences, Kangwon National University, Chunchon 200- 701, Kangwon-Do, Korea
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Corresponding author E-mail: ycpark@kangwon.ac.kr, Tel: 82-33-250-6436

ABSTRACT

Acid phosphatase (AP) in the egg of the lady beetle, Harmonia axyridis, was purified and characterized. Ammonium sulfate precipitation, CM column and isoelectrofocusing (IEF) were applied to purify an estimated molecular weight of 66 kDa AP. The purity was checked by SDS PAGE, native PAGE and Western blot. AP was detected in the hemolymph of the female and the egg, but not in the male on the blotting. Km of AP for a substrate, p-nitrophenyl phosphate (p-NPP), was 1.64 x 10-4 M. AP had the optimum enzymatic activity at pH 3.5. In inhibition tests performed with various chemicals, ammonium molybdate suppressed 99% of the enzyme activity of AP even at the concentration of 5 x 10-4 mM. AP was stable up to 50°C.

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