西南岩溶地区黄荆叶片碳酸酐酶的稳定性

研究表明西南岩溶地区几种植物叶片中含有明显活性的碳酸酐酶(carbonic anhydrase, CA)，从黄荆(Vitex negundo)叶片提取碳酸酐酶，该酶具有良好的热稳定性。阴离子及岩溶环境主要金属离子对碳酸酐酶活性有一定的影响，Ca2+、Mg2+低于10 mmol.L-1，Mn2+ 、Zn2+低于0.01 mmol.L-1，Co2+、Cu2+低于0.001 mmol.L-1，NO3-、Cl-、Br-、I-、NO2-低于0.01 mmol.L-1时，酶活性较稳定。0.001～0.01 mmol.L-1的Ca2+、Mg2+对该酶有激活作用。研究结果表明, 该酶比较适应岩溶土壤水体的离子环境从而保持酶活性的相对稳定。

Stability of Carbonic Anhydrase in Leaves of Vitex negundo in Karst Areas of Southwest China

This paper describes the determination on the activity of carbonic anhydrase (CA,EC4.2.1.1) of plant species in karst areas of Southwest China. CA was extracted from leaves of Vitex negundo. The thermostability of CA and the effects of anions and metallic ions on CA activity were investigated. CA activity was stable at different temperatures and relatively stable when the concentration of Ca2+ and Mg2+ was lower than 10 mmol.L-1; Co2+ and Cu2+ lower than 0.001 mmol.L-1; and Zn2+, Mn2+, NO3-, Cl-, Br-, I- and NO2 - lower than 0.01 mmol.L-1. CA could be activated by Ca2+ and Mg2+ at 0.001~0.01 mmol.L-1. Thus, CA had a relative adaptability and could maintain the activity well in the ions condition of soilwater and karstwater.