有限酶切拟康氏木霉纤维素酶分子研究其结构域的结构与功能  

Analysis of domain's Structure and function of cellulases from Trichoderma pseudokoningii S-38 by Limited proteolysis

作　　者：阎伯旭[1] 孙迎庆[2] 高培基[1] 

机构地区：[1]山东大学微生物技术国家重点实验室,济南250100 [2]北京大学生命科学中心,北京100871

出　　处：《纤维素科学与技术》1998年第3期1-9,共9页Journal of Cellulose Science and Technology

基　　金：国家自然科学基金;国家教委博士点基金

摘　　要：从拟康氏木霉Ｔｒｉｃｈｏｄｅｒｍａ ｐｓｅｕｄｏｋｏｎｉｎｇｉｉＳ－３８菌株发酵液中分离纯化了一个外切葡聚糖纤维二糖水解酶（ＣＢＨＩ，ＣＥ３．２．１．９１）和一个内切葡聚糖酶（ＥＧＩ，ＥＣ３．２．１．４）。经木瓜蛋白酶有限酶切，分别都得到了一个对可溶性底物具有与天然酶相近活力的催化结构域位于天然酶分子的Ｃ端，圆二色谱测定表明其催人域具有与天然酶相似的结构特征。由有限酶切内。Limited protco1ysis of an endopucanase (EG I) and an exocellobiohydrilase (CBH l)from Trichoderma psethefoedi S - 38 vielded respective1y, a catalytic dondn with similarcatalytic activity for souble sudstrate as intact enzyme, and a domain containg two short peptides,which can adsorb insoluble cellulose. The results of C - terminal sequencing suggested that thecatalytic domain of EG I may be located in N - terminal of intact enzyme, and circular dichronism(CD) studies indicated that the catalytic domain disp1ayed a similar conformational propertiescompared to that of intact enzyme. The CBH I molecule has a blocked N - terminal and containedabout 12% of carboydrite,while the carbohydrite of CBH I - core only 1. 5%. Estimate by CDshien that in intact CBH I there wes no 220 nn' s'trough', the a - helical content was alsosmall,and the positive peak at 195nm was present, while the nwtve peak at 205 - 215nm wasabsence,which indicated that the CBH I is a protein with rich B -structre. Studies as decarepH and ligaded cellobiase suggested that the spectroscopic properties of CBH I is dependent on its core.

关 键 词：纤维素酶 葡聚糖酶 有限酶切 结构域 水解酶 

分 类 号：Q556.2[生物学—生物化学] TQ353.14[化学工程]