几种纤维素酶蛋白的双向电泳分析

Analysis of Several Kinds of Cellulases by Two-dimensional Electrophoresis

利用双向电泳技术比较了商品纤维素酶和自产纤维素酶在蛋白组分及蛋白组分含量上的差异。结果表明:自产酶和商品酶的主要蛋白均为外切酶CBH,但在内切酶EG的分泌上存在差异,以蒸汽爆破和稀酸预处理玉米秸秆为碳源的自产纤维素酶A和B,EGⅠ表达量分别占各自分泌组总蛋白的18%和7%,EGⅡ表达量分别占各自分泌组总蛋白的12%和17%,而商品酶EGⅠ和EGⅡ的表达量为分泌总蛋白的6%和10%。自产酶中均具有较高的木聚糖酶(XYN)活性,在谱图中检测到XYNⅠ、XYNⅡ和XYNⅣ蛋白点,而商品纤维素酶只存在XYNⅣ蛋白点。并且自产酶中β-木糖苷酶(BXL)的表达量是商品酶中的5倍。

The differences of proteins and protein content of commercial cellulases,and cellulases from Trichoderma reesei Rut C30 produced in this laboratory were investigated by two-dimensional electrophoresis.The results showed that the main protein of two cellulases preparations,produced in this laboratory and commercial cellulase was CBH,but they had some differences in EG.Firstly,with steam-exploded corn stover as the carbon source,the expression levels of EG Ⅰ and EG Ⅱ accounted for 18 % and 12 % of the secretome in protein content respectively.With dilute acid pretreated corn stover as the carbon source,the expression levels of EG Ⅰ and EG Ⅱ accounted for 7 % and 17 % of the secretome respectively.Then the expression levels of EGⅠ and EGⅡ,in the commercial cellulase,accounted for 6 % and 10 % of the secretome respectively.Secondly,such enzymes as XYNⅠ,XYNⅡ and XYN Ⅳwere detected in cellulase preparations from this laboratory,while commercial cellulase contained only XYN Ⅳ.The expression level of β-xylosidase（BXL）in cellulase preparations from this laboratory,was 5 times of that in commercial cellulase.