Purification and properties of two types of soluble trehalases from embryonic larvae of the silkworm, Bombyx mori
2006
Huang, J.(Kyoto Inst. of Technology (Japan)) | Furusawa, T. | Sadakane, K. | Sugimura, Y.
In order to determine the properties of trehalase in the developing eggs of Bombyx mori, soluble-type trehalase was purified from the supernatant of egg homogenate by acid treatment, column chromatographies of Sephacryl S-300, DEAE-cellulofine and Con A-Sepharose, and preparative polyacrylamide gel electrophoresis. Two peaks of trehalase activity were detected by gel filtration column chromatography, and designated as P I (73 kDa) and P II (140 kDa). P I and P II were eluted as a single peak from ion exchange column chromatography at about 0.2 M and 0.25 M of NaCl, respectively. Subunit molecular masses of P I and P II were estimated as approximately 64 kDa on SDS-PAGE and Western blot analysis. P I had a Ksub(m) of 1.56 mM for trehalose and an optimal pH around 6.5 with an activation energy of 11.03 kCal/mol. P II had a Ksub(m) of 0.44 mM for trehalose and an optimal pH around 5.5 with an apparently lower activation energy of 5.92 kCal/mol. These results suggest that two types of soluble trehalase are present in the embryonic larvae of the silkworm, Bombyx mori.
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