内切纤维素酶检测试剂盒 英文名称: endo-Cellulase Assay Kit |
型号:null 产品货号: K-CELLG3 |
价格:请致电:010-57128832,18610462672 |
品牌: 爱尔兰 |
品牌: Megazyme 产品货号:K-CELLG3 品牌:Megazyme 产品品名:内切纤维素酶检测试剂盒 英文品名:endo-Cellulase Assay Kit 规格型号:180/360 A soluble substrate for the specific measurement of cellulase(endo-1,4-β-glucanase) in enzyme preparations and fermentation products. INTRODUCTION: Cellulase (endo-1,4-β-glucanase) plays a key role in the hydrolysis of cellulosic biomass to fermentable sugars. This enzyme also finds widespread industrial applications in the modification of cellulosic materials and in the degradation of mixed linkage 1,3;1,4-β-glucans. Numerous methods are available for the measurement of cellulase, including those based on increase in reducing sugar levels on hydrolysis of CM-cellulose or 1,3:1,4-β-glucan1. endo-Cellulase can be specifically assayed using viscometric methods with soluble CM-cellulose 7M as substrate, or by employing soluble or insoluble (crosslinked) dyed cellulose or mixed-linkage β-glucan. In general, assays based on the use of dyed polysaccharides are standardised against a reducing sugar method that employs either CM-cellulose or β-glucan as substrate. The problem here is that these polysaccharide substrates are not completely defined and thus lead to some variation in the values obtained. The Megazyme CellG3, cellulase test reagent, employs high purity β-glucosidase and benzylidene blocked, 2-chloro-4-nitrophenyl-β-Dcellotrioside (BClPNPβ-G3). The level of β-glucosidase used ensures maximum sensitivity of the assay. On hydrolysis of BClPNPβ-G3 to benzylidene blocked cellobiose and 2-Cl-4-nitrophenyl-β-D-glucose by cellulase, the 2-Cl-4-nitrophenyl-β-D-glucose is immediately cleaved to D-glucose and free 2-Cl-4-nitrophenol (ClPNP) by the β-glucosidase present in the substrate mixture (Scheme 1). Thus, the rate of release of ClPNP relates directly to the rate of hydrolysis of BClPNPβ-G3 by cellulase. The reaction is stopped, and the phenolate colour is developed, on addition of Trizma base solution (pH 9). Standard curves relating enzyme activity to increase in absorbance at 400 nm on hydrolysis of BClPNPβ-G3 by Trichoderma and A. niger cellulases are shown in Figures 1 and 2. A standard curve relating enzyme activity on CM-cellulose 4M (Nelson/Somogyi reducing sugar assay2) to absorbance increase at 400 nm on incubation of Trichoderma cellulase with BClPNPβ-G3 is shown in Figure 3. Cellulase enzymes from different sources vary in their ability to hydrolyse BClPNPβ-G3, so it is necessary to establish a specific standard curve for each cellulase to allow accurate quantitation. The assay can be used at temperatures up to 80°C and in the pH range of 4.5 to 8.0. With cellulase enzymes with activity at high pH values, it is necessary to terminate the reaction with tri-sodium phosphate (pH 11.0). Of the cellulases evaluated in the current study, that with the lowest rate of hydrolysis of BClPNPβ-G3 was the cellulase from A. niger (E-CELAN, Megazyme). BClPNPβ-G3 substrate solution as supplied in dimethyl sulphoxide (DMSO) is very stable when stored at 4°C or 1 -20°C. The substrate, CellG3 is stable for at least 7 days at 4°C and for > 2 years at -20°C. KITS: Kits suitable for performing 180 / 360 assays are available from Megazyme. The kits contain the full assay method plus: Bottle 1: (x2) Benzylidene blocked, 2-chloro-4-nitrophenyl-β-Dcellotrioside (BClPNPβ-G3; 3 mL) in DMSO. Stable for > 2 years at -20°C. Bottle 2: KCl solution (15 mL, 100 mM) plus sodium azide (0.02% w/v). Stable for approx. 4 years at 4°C. Bottle 3: Thermostable β-glucosidase (0.40 mL, 400 U/mL) in 50% w/v ammonium sulphate solution plus sodium azide (0.02% w/v). Stable for approx. 4 years at 4°C. Bottle 4: Trichoderma cellulase standard solution (5 mL, ~ 1.6 U/mL; actual value stated on the vial label) in 50% aqueous glycerol plus sodium azide (0.02% w/v). Stable for approx. 4 years at -20°C. 温馨提示:需要详细的产品使用说明书,请联系甄准生物客服人员,我们将竭诚为您服务。 甄准,甄心倾听您每一个标准! |