Bibliographic Details
| Title: |
Cellulase Complex of the Fungus Chrysosporium lucknowense: Isolation and Characterization of Endoglucanases and Cellobiohydrolases. |
| Authors: |
Bukhtojarov, F.E.1, Ustinov, B.B.1, Salanovich, T.N.1, Antonov, A.I.1, Gusakov, A.V.1 avgusakov@enzyme.chem.msu.ru, Okunev, O.N.2, Sinitsyn, A.P.1 |
| Superior Title: |
Biochemistry (00062979). May2004, Vol. 69 Issue 5, p542-551. 10p. |
| Subject Terms: |
*CELLULASE, *HYDROLASES, *FUNGI, *CELLULOSE 1,4-beta-cellobiosidase, *GLUCANS, *CELLULOSE, *FUNGAL enzymes, *ENZYMES |
| Abstract: |
Using different chromatographic techniques, eight cellulolytic enzymes were isolated from the culture broth of a mutant strain of Chrysosporium lucknowense: six endoglucanases (EG: 25 kD, pI4.0; 28 kD, pI5.7; 44 kD, pI6.0; 47 kD, pI 5.7; 51 kD, pI4.8; 60 kD, pI3.7) and two cellobiohydrolases (CBH I, 65 kD, pI4.5; CBH II, 42 kD, pI4.2). Some of the isolated cellulases were classified into known families of glycoside hydrolases: Ce16A (CBH II), Ce17A (CBH I), Cell 2A (EG28), Ce145A (EG25). It was shown that EG44 and EG51 are two different forms of one enzyme. EG44 seems to be a catalytic module of an intact EG51 without a cellulose-binding module. All the enzymes had pH optimum of activity in the acidic range (at pH 4.5-6.0), whereas EG25 and EG47 retained 55-60% of the maximum activity at pH 8.5. Substrate specificity of the purified cellulases against carboxymethylcellulose (CMC), β-glucan, Avicel, xylan, xyloglucan, laminarin, and p-nitrophenyl-β-D-cellobioside was studied. EG44 and EG51 were characterized by the highest CMCase activity (59 and 52 U/mg protein). EG28 had the lowest CMCase activity (11 U/mg) amongst the endoglucanases; however, this enzyme displayed the highest activity against β-glucan (125 U/mg). Only EG51 and CBH I were characterized by high adsorption ability on Avicel cellulose (98-99%). Kinetics of Avicel hydrolysis by the isolated cellulases in the presence of purified β-glucosidase from Aspergillus japonicus was studied. The hydrolytic efficiency of cellulases (estimated as glucose yield after a 7-day reaction) decreased in the following order: CBH I, EG6O, CBH II, EG51, EG47, EG25, EG28, EG44. [ABSTRACT FROM AUTHOR] |
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| Database: |
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