大鵟消化系统蛋白水解酶种类和活性分析

采用蛋白水解酶复性电泳(G-PAGE)技术对大(Buteo hemilasius)消化系统5种器官腺胃、胰脏、十二指肠、空肠、大肠蛋白水解酶的种类和性质进行了研究,以期为研究野生鸟类的分类地位、系统演化提供基础资料,结果表明,①受pH值的影响和制约,大消化系统蛋白水解酶的活性在碱性、中性与酸性条件下递减;②在酸性条件下,45 ku蛋白水解酶存在于除腺胃外的各受检器官;③pH 7.0时,腺胃、胰脏酶谱相似,均含有683、5、342、0 ku的蛋白水解酶;④pH 8.0时,空肠和十二指肠的蛋白水解酶种类最多、活性最强,分别检出8种和7种蛋白水解酶。总之,pH值对蛋白水解酶的活性有明显的制约作用,46、41ku蛋白水解酶随着pH值的增高而失去活性,为酸性蛋白水解酶,250、2064、5 ku蛋白水解酶随着pH值的增高活性逐渐增强,为碱性蛋白水解酶。十二指肠和空肠的蛋白水解酶种类多、活性强,可能为蛋白质消化的主要场所。

Analysis of Proteolytic Enzymes in Digestive System of Buteo hemilasius

The proteolytic enzymes in glandular stomach,pancreases,duodenum,jejunum,and large intestine,in digestive system of Buteo humilities were studied with gelatine polyacrylamide gel-electrophoresis(G-PAGE) to provide basic information for studying wild birds.The activities of proteolytic enzymes became weaker with the decrease in pH.In acid environment,the 45 ku proteolytic enzyme existed in all organs examined except for glandular stomach.When the pH was 7.0,similar patterns of proteolytic enzymes existed in glandular stomach and pancreas,both showing 68,35,34,and 20 ku proteolytic enzymes.When pH was increased to 8.0,8 and 7 kinds of proteolytic enzymes were observed in duodenum and jejunum respectively,and their proteolytic activities were the strongest.In summary,proteolytic enzymes in digestive organs varied evidently under different pH conditions and the proteolytic enzyme activity was affected by pH.With the pH increase,46 and 41 ku proteolytic enzymes lose their activities,while 250,206,and 45 ku proteolytic enzymes are alkaline proteolytic enzymes.Among the five organs in the digestive system of B.hemilasius,more proteolytic enzymes and high enzyme activities exist in duodenum and jejunum,where might be the main places of protein digestion.