白鹭和牛背鹭肠蛋白酶理化特性的研究  

The Physiochemical Characteristics of Intestine Proteinase Taken from Little Egret and Cattle Egret

作　　者：朱开建[1] 陈小麟[1] 许玉德[1] 王博 陈宗团 

机构地区：[1]厦门大学生命科学学院,福建厦门361005 [2]厦门白鹭自然保护区管理处,福建厦门361004

出　　处：《厦门大学学报（自然科学版）》2005年第1期128-131,共4页Journal of Xiamen University：Natural Science

基　　金：福建省自然科学基金( D9910003 );厦门科技项目(3502Z20031104)项目

摘　　要：对白鹭(Egretta garzetta)和牛背鹭(Bubulcus ibis)雏鸟肠蛋白酶进行研究.两种鹭类的肠蛋白酶存在着许多共同的理化特性,包括分子量(39.4 kD)、等电点(5.4~7.5)、耐热性、抗冻融能力、最适温度(65℃)、最适 pH(9.0 和 8.6)等,而且两种鹭类的肠道蛋白酶对重金属离子Ag+和Hg2+、EDTA、或 Ca2+ 和 Mg2+ 的影响也表现出相同的反应.白鹭和牛背鹭的肠蛋白酶比活力存在着不显著的差异(1.63±0.62SE和 2.21±0.80SE)( 'P>0.05).白鹭和牛背鹭肠道蛋白酶为中性蛋白酶.活性中心的研究表明:两种鹭类的肠道蛋白酶的活性中心都含有色氨酸和丝氨酸残基,但是不含精氨酸、半胱氨酸和氨基,因此,主要为丝氨酸蛋白酶.The intestine proteinases taken from nestling of Little Egret(Egretta garzetta)and Cattle Egret (Bubulcus ibis) were studied.The characteristics of intestine proteinase were similar between the two egret species, which included molecular weight ((39.4) kD),PI (from 5.4 to 7.5),thermal-stability,optimal temperature(65℃)and optimal pH value(9.0 and 8.6 for Little Egret and Cattle Egret respectively).The intestine proteinase of the two egret species had the same responses to the effect of Ag^+ and Hg^(2+),EDTA ,or Mg^(2+) and Ca^(2+).No significant difference of the relative activities of the intestine proteinase were found between Little Egret and Cattle Egret(1.63±0.62 SE unit/μg and 2.21±0.80 SE unit/μg respectively).Both intestine proteinases from Little Egret and Cattle Egret were dispases.The modification results of active central group indicated that the proteinase in two ardeids similarly had the serine residue and tryptophane residue,but hadn’t amino residue,arginine residue or cysteine residue.These results suggested that intestine proteinase in ardeids should mainly be serine proteinase.

关 键 词：牛背鹭 白鹭 最适PH 雏鸟 最适温度 比活力 活性中心 和牛 理化特性 肠道 

分 类 号：Q959[生物学—动物学] S823[农业科学—畜牧学]