α-Amylase from developing embryos of the camel tick Hyalomma dromedarii

被引:7
|
作者
Mohamed, SA [1 ]
机构
[1] Natl Res Ctr, Dept Mol Biol, Cairo, Egypt
关键词
camel; tick; Hyalomma dromedarii; embryogenesis; alpha-amylases; purification; characterization;
D O I
10.1016/S0305-0491(00)00165-6
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
alpha-Amylase activity in the camel tick Hyalomma dromedarii was followed throughout embryogenesis. During purification of alpha-amylase III to homogeneity, ion exchange chromatography lead to four separate forms (termed I, II, III and IV). alpha-Amylase III with the highest specific activity was pure after chromatography on Sephacryl S-300. The molecular mass of alpha-amylase III was 106 kDa for the native enzyme, composed of two subunits of 43 and 66 kDa, respectively. alpha-Amylase had a value of 10 mg starch/ml. Varying alpha-amylase activity was detected when supplied with various substrates. alpha-Amylase III had a temperature optimum at 40 degrees C with heat stability up to 50 degrees C, and a pH optimum of 7.0. The enzyme activity was activated by CaCl2, MgCl2 and NaNO3, but not activated by NaCl, p-CMB, N-ethylmaleimide and iodoacetamide. EDTA and beta-mercaptoethanol strongly inhibited activity. (C) 2000 Elsevier Science Inc. All rights reserved.
引用
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页码:99 / 108
页数:10
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