Identification And Characterization Of P. Nucleorum Larvae Myosin

The objective of this work was to isolate myosin-like ATPase from the soluble fraction of P. nucleorum larvae. The soluble fraction was frozen at -20 oC, thawed after 48 h and centrifuged at 45,000g x 40 minutes. The precipitate was successively washed with buffer (pH 7.5 and 9.0) and ATPase was then solubilized with buffer (pH 9.0) containing 0.5M NaCl. The main polypeptides presented Mr of 205 and 43 kDa and identification by PMF shows similarity of p205 with myosin heavy chain of Tribolium castaneum. That fraction expressed Ca2+-ATPase activity and actinstimulated Mg2+-ATPase activity. The Ca2+-ATPase activity was inhibited by magnesium but not by 140 µM thapsigargin, 1.7 mM ouabain or 1 mM azide.