血管紧张素转换酶的固相化与性质  

Immobilization and Properties of Angiotensin Converting Enzyme

作　　者：刘宏[1] 陈兰英[1] 

机构地区：[1]中国医学科学院中国协和医科大学阜外心血管病研究所生化研究室,北京100037

出　　处：《中国医学科学院学报》2000年第6期558-561,共4页Acta Academiae Medicinae Sinicae

基　　金：国家新药研究基金!( 96- 901- 05- 85)

摘　　要：目的为从天然肽类混合物中分离血管紧张素转换酶（ angiotensin converting enzyme, ACE）抑制活性物质，对固相化 ACE（固相酶）进行研究。方法在低水活度条件下利用苯甲磺酰氯活化 Sepharose CL- 4B凝胶侧链基团上的羟基，形成高反应活性的苯磺酰基团，通过与 ACE上的氨基反应将酶固定于琼脂糖凝胶。结果固相化 ACE的反应 pH范围较宽，最适反应 pH比溶液酶（自由酶）增加 0.6个单位，达到 8.8。分别在 pH9.0和 pH6.5条件下处理 24 h，固相酶活力保留 82％和 68％，溶液酶只剩下 64％和 39％。两种酶均在 50℃左右活力最大，温度继续升高溶液酶迅速失活。分别在 40℃和 50℃处理 2 h，固相酶剩余活力为 82％和 34％，溶液酶为 52％和完全失活。 20℃放置 1个月，固相酶剩余活力为 61％，而溶液酶只有 20％。结论 ACE固相酶在 pH和温度稳定性方面强于溶液酶。To study the immobilization of angiotensin converting enzyme (ACE)for purifying ACE inhibitor from a native peptide mixture. Methods The experiment was carried out under the low water activity condition, using tosylate chloride activating side- chain hydroxyl group of Sepharose CL- 4B agarose to form a high active group which could react with the free amino- group of ACE to link the enzyme with agarose. Results Immobilized ACE not only had a wider pH range, but also had a 0.6 unit right- move optimum pH than soluble ACE. After treated in pH9.0 and pH6.5 conditions for 24 h respectively, 82％ and 68％ enzyme activities of immobilized ACE was maintained, and soluble ACE remained 64％ and 39％ . Immobilized and soluble ACE both appeared maximum enzyme activity at about 50℃ , the soluble ACE would lose almost all its activity when temperature kept rising. When kept at 40℃ and 50℃ for 2 h, the activity of immobilized ACE remained 82％ and 34％ respectively, while the soluble ACE remained 52％ and completely inactivated. After two kinds of enzymes were stored at 20℃ for one month, immobilized ACE remained 61％ activity,as compared with the 20％ activity residual of soluble ACE. Conclusion The immobilized ACE had a better stability than soluble ACE in conditioned pH and temperature.

关 键 词：血管紧张素转换酶 固相酶 溶液酶 酶稳定性 

分 类 号：Q555[生物学—生物化学]