›› 2006, Vol. 49 ›› Issue (2): 189-193.

• RESEARCH PAPERS • Previous Articles     Next Articles

Activity sensitivity of midgut α-amylase in larvae of the armyworm, Pseudaletia separata Walker (Lepidoptera: Noctuidae)

  

  • Online:2006-05-15 Published:2006-11-20

Abstract:

The effects of different enzymatic buffers, pH value, chloridion, and oxadiazolyl pyridazinone on the midgut α-amylase activity in 5th-instar 2nd-day larvae of Pseudaletia separata Walker were assayed. The results showed that sodium acetate buffer (pH 5.8) and phosphate buffer (pH 8.0) were most beneficial to α-amylase activity in their buffer series with different pH value, with the maximal activity as high as 4.49 and 4.97 U respectively. The activities against 5, 10, 20, 40, 80 mmol/L chloridion showed first decreasing and then increasing in sodium acetate buffer (pH 5.8), whereas they showed only gradually decreasing in phosphate buffer (pH 8.0). Inhibition of 1.4 mmol/L oxadiazolyl pyridazinone against α-amylase activity was as high as 70 percent, and thereafter gradually decreased with the increase of α-amylase protein.


Key words: Pseudaletia separata, α-amylase, enzyme activity, pH value, chloridion, oxadiazolyl pyridazinone