【摘要】 通过对河北省邯郸地区和山东省冠县的棉铃虫（Helicoverpa armigera H（?）bner）乙酰胆碱酯酶（AChE）研究,结果表明,棉铃虫乙酰胆碱酯酶对乙酰硫代胆碱（ATCh）和乙酰-β-甲基硫代胆碱（MeTCh）的比活力以及米氏常数(K_?)值随其发育阶段呈有规律的变化,AChE比活力在幼虫期呈现两个高峰,一个在三龄,另一个在化蛹前;在蛹期AChE比活力没有明显的变化,而且比活力值比较低;到成虫期第4天有一个明显的高峰,比活力值高于其它任何虫态。K_?和最大反应速度(V_max)的变化趋势基本上与比活力一致。棉铃虫AChE的K_?和比活力随其生长发育阶段的周期性变化对于指导用有机磷和氨基甲酸酯类杀虫药剂的化学防治具有重要的意义。不同地点采集到的棉铃虫AChE对AICh和MeTCh水解的活化能有所不同,邯郸地区的棉铃虫AChE水解MeTCh的活化能,蛹和成虫是幼虫期的3.9-4.3倍,而冠县棉铃虫水解MeTCh的活化能则变化不大。AChE水解ATCh的活化能,邯郸地区棉铃虫的AChE不同虫态间变化不大,冠县棉铃虫AChE,幼虫和成虫期约是蛹期的4倍。这说明不同生长发育时期,棉铃虫AChE对底物的水解所消耗的能量是不同的。棉铃虫幼虫AChE的最适反应条件是酶量以重量计为50-100mg,反应时间为10-20min,反应温度为35℃,反应体系的pH值为8.0。更多还原

【Abstract】 The substrate specificity and developmental changes of acetylcholinesterase (AChE) of cotton bollworm, Helicoverpa armigera Hiibner, were investigated during 1991 to 1994. The insects were collected from Handan suburbs of Hebei Province and Guan County of Shandong Province. The re-sults show that the specific activity and Michaelis constants (km) of AChE toward acetylthiocholine (ATCH) and acetyl-β-methyl-thiocholine (MeTCh) regularly varied with the developmental stage of cotton bollworm. The two peaks of the specific activity were observed respectively in the third instar and sixth instar of larvae. The specific activity of AChE in pupae was the lowest and that in heads of four-days moth was the highest in various developmental stages of cotton bollworms. The tendency of Km and maximum velocity (Vmax) was identical with the change of specific activity in the AChEs of cot-ton bollworm. The activation energy (Ea) of AChE toward MeTCh in pupae and adults was 3. 9-4. 3 times as much as that of larvae in cotton bollworms from Handan of Hebei Province. It suggests that the spending energies of AChE for hydrolysing substrate are different in larva, pupa and adult. The op-timum conditions of AChE reaction with ATCh in larvae were 50-100 mg of tissue weights for the amount of enzyme, 10-20 minutes for the reaction time, 35℃ for the reaction temperature and 8. 0 for the reaction pH value.更多还原