Kim, Su Jung Joo, Ji Eun Jeon, Sang Duck Hyeon, Jeong Eun Kim, Seung Wook Um, Young Soon Han, Sung Ok 2024-01-20T04:30:29Z 2024-01-20T04:30:29Z 2021-09-05 2016-05 0141-8130 https://pubs.kist.re.kr/handle/201004/124112 This is the first study for therrmostable mutants of mesophilic endoglucanase EngZ from Clostridium cellulovorans using by site-directed mutagenesis. K94R, S365P and their double mutant K94R/S365P had a wide range of active temperatures (30-60 degrees C). In addition, the optimal temperature of K94R/S365P was increased by 7.5 degrees C. K94R/S365P retained 78.3% relative activity at 70 degrees C, while the wild type retained only 5.8%. Especially, K94R/S365P remained 45.1-fold higher activity than the wild type at 70 degrees C. In addition, K94R/S365P was 3.1-fold higher activity than the wild type at 42.5 degrees C, which is the optimal temperature of the wild type. K94R/S365P showed also stimulated in 2.5-fold lower concentration of CaCl2 and delayed aggregation temperature in the presence of CaCl2 compared to the wild type. In pH stability, K94R/S365P was not influenced, but the optimum pH was transferred from pH 7 to pH 6. In long-term hydrolysis, K94R/S365P reduced the newly released reducing sugar yields after 12 h reaction; however, the yields consistently increased until 72 h. Finally, the total reducing sugar of K94R/S365P was 5.0-fold higher than the wild type at 50 degrees C, pH6. EngZ (K94R/S365P) can support information to develop thermostability of GH9 endoglucanase with a high catalytic efficiency as the potential industrial bioprocess candidate. (C) 2016 Elsevier B.V. All rights reserved. English Elsevier BV Enhanced thermostability of mesophilic endoglucanase Z with a high catalytic activity at active temperatures Article 10.1016/j.ijbiomac.2016.01.068 1 International Journal of Biological Macromolecules, v.86, pp.269 - 276 International Journal of Biological Macromolecules 86 269 276 N scie scopus 000374196100033 2-s2.0-84956611496 Biochemistry & Molecular Biology Chemistry, Applied Polymer Science Biochemistry & Molecular Biology Chemistry Polymer Science Article CELL-SURFACE HYDROLYSIS ACID COMPLEXES PROTEINS DISPLAY EngZ Thermostability Cellulolytic efficiency Family 9 endoglucanase Site-directed mutagenesis