Mutational Analysis of Thermus caldophilus GK24 ${\beta}$-Glycosidase: Role of His119 in Substrate Binding and Enzyme Activity

  • Oh, Eun-Joo (Department of Genetic Engineering, Sungkyunkwan University) ;
  • Lee, Yoon-Jin (Department of Genetic Engineering, Sungkyunkwan University) ;
  • Choi, Jeong-Jin (Department of Genetic Engineering, Sungkyunkwan University) ;
  • Seo, Moo-Seok (Department of Genetic Engineering, Sungkyunkwan University) ;
  • Lee, Mi-Sun (Department of Genetic Engineering, Sungkyunkwan University) ;
  • Kim, Gun-A (Department of Genetic Engineering, Sungkyunkwan University) ;
  • Kwon, Suk-Tae (Department of Genetic Engineering, Sungkyunkwan University)
  • Published : 2008.02.29

Abstract

Three amino acid residues (His119, Glu164, and Glu338) in the active site of Thermus caldophilus GK24 ${\beta}$-glycosidase (Tca ${\beta}$-glycosidase), a family 1 glycosyl hydrolase, were mutated by site-directed mutagenesis. To verify the key catalytic residues, Glu164 and Glu338 were changed to Gly and Gln, respectively. The E164G mutation resulted in drastic reductions of both ${\beta}$-galactosidase and ${\beta}$-glucosidase activities, and the E338Q mutation caused complete loss of activity, confirming that the two residues are essential for the reaction process of glycosidic linkage hydrolysis. To investigate the role of His119 in substrate binding and enzyme activity, the residue was substituted with Gly. The H119G mutant showed 53-fold reduced activity on 5mM p-nitrophenyl ${\beta}$-D-galactopyranoside, when compared with the wild type; however, both the wild-type and mutant enzymes showed similar activity on 5mM p-nitrophenyl ${\beta}$-D-glucopyranoside at $75^{\circ}C$. Kinetic analysis with p-nitrophenyl ${\beta}$-D-galactopyranoside revealed that the $k_{cat}$ value of the H119G mutant was 76.3-fold lower than that of the wild type, but the $K_m$ of the mutant was 15.3-fold higher than that of the wild type owing to the much lower affinity of the mutant. Thus, the catalytic efficiency $(k_{cat}/K_m)$ of the mutant decreased to 0.08% to that of the wild type. The $k_{cat}$ value of the H119G mutant for p-nitrophenyl ${\beta}$-D-glucopyranoside was 5.l-fold higher than that of the wild type, but the catalytic efficiency of the mutant was 2.5% of that of the wild type. The H119G mutation gave rise to changes in optima pH (from 5.5-6.5 to 5.5) and temperature (from $90^{\circ}C\;to\;80-85^{\circ}C$). This difference of temperature optima originated in the decrease of H119G's thermostability. These results indicate that His119 is a crucial residue in ${\beta}$-galactosidase and ${\beta}$-glucosidase activities and also influences the enzyme's substrate binding affinity and thermostability.

Keywords

References

  1. Aguilar, C. F., I. Sanderson, M. Moracci, M. Ciaramella, R. Nucci, M. Rossi, and L. H. Pearl. 1997. Crystal structure of the $\beta-glycosidase$ from the hyperthermophilic archeon Sulfolobus solfataricus: Resilience as a key factor in thermostability. J. Mol. Biol. 271: 789-802 https://doi.org/10.1006/jmbi.1997.1215
  2. Akiba, T., M. Nishio, I. Matsui, and K. Harata. 2004. X-ray structure of a membrane-bound $\beta-glycosidase$ from the hyperthermophilic archaeon Pyrococcus horikoshii. Proteins 57: 422-431 https://doi.org/10.1002/prot.20203
  3. Barrett, T., C. G. Suresh, S. P. Tolley, E. J. Dodson, and M. A. Hughes. 1995. The crystal structure of a cyanogenic $\beta-glycosidase$ from white clover, a family 1 glycosyl hydrolase. Structure 3: 951-960 https://doi.org/10.1016/S0969-2126(01)00229-5
  4. Burmeister, W. P., S. Cottaz, H. Driguez, R. Iori, S. Palmieri, and B. Henrissat. 1997. The crystal structures of Sinapis alba myrosinase and a covalent glycosyl-enzyme intermediate provide insights into the substrate recognition and active-site machinery of an S-glycosidase. Structure 5: 663-675 https://doi.org/10.1016/S0969-2126(97)00221-9
  5. Choi, J. J., E.-J. Oh, Y.-J. Lee, D. S. Suh, J. H. Lee, S. W. Lee, H. T. Shin, and S.-T. Kwon. 2003. Enhanced expression of the gene for $\beta-glycosidase$ of Thermus caldophilus GK24 and synthesis of galacto-oligosaccharides by the enzyme. Biotechnol. Appl. Biochem. 38: 131-136 https://doi.org/10.1042/BA20020119
  6. Czjzek, M., M. Cicek, V. Zamboni, W. P. Burmeister, D. R. Bevan, B. Henrissat, and A. Esen. 2001. Crystal structure of a monocotyledon (maize ZMGlu1) $\beta-glucosidase$ and a model of its complex with $\rho-nitrophenyl$ $\beta-D-thioglucoside$. Biochem. J. 354: 37-46 https://doi.org/10.1042/0264-6021:3540037
  7. Davies, G. and B. Henrissat. 1995. Structures and mechanisms of glycosyl hydrolases. Structure 3: 853-859 https://doi.org/10.1016/S0969-2126(01)00220-9
  8. Han, K.-W., J. Yoo, E.-J. Oh, J. J. Choi, H.-K. Kim, and S.-T. Kwon. 2001. Cloning, analysis and expression of the gene for $\beta -glycosidase$ of Thermus caldophilus GK24 and properties of the enzyme. Biotechnol. Lett. 23: 379-384 https://doi.org/10.1023/A:1005628106138
  9. Hancock, S. M., K. Corbett, A. P. Fordham-Skelton, J. A. Gatehouse, and B. G. Davis. 2005. Developing promiscuous glycosidases for glycoside synthesis: Residues W433 and E432 in Sulfolobus solfataricus $\beta-glycosidase$ are important glucosideand glucosideand galactoside-specificity determinants. ChemBioChem 6:866-875 https://doi.org/10.1002/cbic.200400341
  10. Henrissat, B. and A. Bairoch. 1996. Updating the sequencebased classification of glycosyl hydrolases. Biochem. J. 316: 695-696 https://doi.org/10.1042/bj3160695
  11. Ho, S. N., H. D. Hunt, R. M. Horton, J. K. Pullen, and L. R. Pease. 1989. Site-directed mutagenesis by overlap extension using the polymerase chain reaction. Gene 77: 51-59 https://doi.org/10.1016/0378-1119(89)90358-2
  12. Husebye, H., S. Arzt, W. P. Burmeister, F. V. Härtel, A. Brandt, J. T. Rossiter, and A. M. Bones. 2005. Crystal structure at 1.1 Å resolution of an insect myrosinase from Brevicoryne brassicae shows its close relationship to $\beta-glycosidase$. Insect Biochem. Mol. Biol. 35: 1311-1320 https://doi.org/10.1016/j.ibmb.2005.07.004
  13. Kaper, T., H. H. van Heusden, B. van Loo, A. Vasella, J. van der Oost, and W. M. de Vos. 2002. Substrate specificity engineering of $\beta-mannosidase$ and $\beta-glycosidase$ from Pyrococcus by exchange of unique active site residues. Biochemistry 41: 4147-4155
  14. Kaper, T., J. H. G. Lebbink, J. Pouwels, J. Kopp, G. E. Schulz, J. van der Oost, and W. M. de Vos. 2000. Comparative structural analysis and substrate specificity engineering of the hyperthermostable $\beta-glucosidase$ CelB from Pyrococcus furiosus. Biochemistry 39: 4963-4970 https://doi.org/10.1021/bi992463r
  15. Kim, J. D. and C. G. Lee. 2007. Purification and characterization of extracellular $\beta-glucosidase$ from Sinorhizobium kostiense AFK-13 and its algal lytic effect on Anabaena flos-aquae. J. Microbiol. Biotechnol. 17: 745-752
  16. Kim, S. J., C.-M. Lee, M.-Y. Kim, Y.-S. Yeo, S.-H. Yoon, H.-C. Kang, and B.-S. Koo. 2007. Screening and characterization of an enzyme with $\beta-glucosidase$ activity from environmental DNA. J. Microbiol. Biotechnol. 17: 905-912
  17. Laemmli, U. K. 1970. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature 227: 680-685 https://doi.org/10.1038/227680a0
  18. Lowry, O. H., N. J. Rosebrough, A. J. Farr, and R. J. Randall. 1951. Protein measurement with the Folin phenol reagent. J. Biol. Chem. 193: 265-275
  19. Marana, S. R. 2006. Molecular basis of substrate specificity in family 1 glycoside hydrolases. IUBMB Life 58: 63-73
  20. Marana, S. R., E. H. P. Andrade, C. Ferreira, and W. R. Terra. 2004. Investigation of the substrate specificity of a $\beta-glycosidase$ from Spodoptera frugiperda using site-directed mutagenesis and bioenergetics analysis. Eur. J. Biochem. 271: 4169-4177 https://doi.org/10.1111/j.1432-1033.2004.04354.x
  21. McCarter, J. D. and S. G. Withers. 1994. Mechanisms of enzymatic glycoside hydrolysis. Curr. Opin. Struct. Biol. 4: 885-892 https://doi.org/10.1016/0959-440X(94)90271-2
  22. McIntosh, L. P., G. Hand, P. E. Johnson, M. D. Joshi, M. Korner, L. A. Plesniak, L. Ziser, W. W. Wakarchuk, and S. G. Withers. 1996. The $pK_{a}$ of the general acid/base carboxyl group of a glycosidase cycles during catalysis: A $^{13}C-NMR$ study of Bacillus circulans xylanase. Biochemistry 35: 9958-9966 https://doi.org/10.1021/bi9613234
  23. Moracci, M., L. Capalbo, M. Ciaramella, and M. Rossi. 1996. Identification of two glutamic acid residues essential for catalysis in the $\beta-glycosidase$ from the thermoacidophilic archaeon Sulfolobus solfataricus. Protein Eng. 9: 1191-1195 https://doi.org/10.1093/protein/9.12.1191
  24. Nucci, R., M. Moracci, C. Vaccaro, N. Vespa, and M. Rossi. 1993. Exo-glucosidase activity and substrate specificity of the $\beta-glycosidase$ isolated from the extreme thermophile Sulfolobus solfataricus. Biotechnol. Appl. Biochem. 17: 239-250
  25. Onishi, H. R., J. S. Tkacz, and J. O. Lampen. 1979. Glycoprotein nature of yeast alkaline phosphatase: Formation of active enzyme in the presence of tunicamycin. J. Biol. Chem. 254: 11943-11952
  26. Park, N.-Y., J. Cha, D.-O. Kim, and C.-S. Park. 2007. Enzymatic characterization and substrate specificity of thermostable $\beta-glycosidase$ from hyperthermophilic archaea, Sulfolobus shibatae, expressed in E. coli. J. Microbiol. Biotechnol. 17: 454-460
  27. Sanz-Aparicio, J., J. A. Hermoso, M. Martinez-Ripoll, J. L. Lequerica, and J. Polaina. 1998. Crystal structure of $\beta-glucosidase$ A from Bacillus polymyxa: Insights into the catalytic activity in family 1 glycosyl hydrolases. J. Mol. Biol. 275: 491-502 https://doi.org/10.1006/jmbi.1997.1467
  28. Schulte, D. and W. Hengstenberg. 2000. Engineering the active center of the $6-phospho-\beta -galactosidase$ from Lactococcus lactis. Protein Eng. 13: 515-518 https://doi.org/10.1093/protein/13.7.515
  29. Trimbur, D. E, R. A. J. Warren, and S. G. Withers. 1992. Region-directed mutagenesis of residues surrounding the active site nucleophile in beta-glucosidase in Agrobacterium faecalis. J. Biol. Chem. 267: 10248-10251
  30. Vallmitjana, M., M. Ferrer-Navarro, R. Planell, M. Abel, C. Ausin, E. Querol, A. Planas, and J. A. Perez-Pons. 2001. Mechanism of the family 1 $\beta-glucosidase$ from Streptomyces sp.: Catalytic residues and kinetic studies. Biochemistry 40: 5975-5982 https://doi.org/10.1021/bi002947j
  31. Wang, Q., D. E. Trimbur, R. Graham, R. A. Warren, and S. G. Withers. 1995. Identification of the acid/base catalysis in Agrobacterium facecalis beta-glucosidase by kinetic analysis of mutants. Biochemistry 7: 14554-14562
  32. Wang, X., X. He, S. Yang, X. An, W. Chang, and D. Liang. 2003. Structural basis for thermostability of $\beta-glycosidase$ from the thermophilic eubacterium Thermus nonproteolyticus HG102. J. Bacteriol. 185: 4248-4255 https://doi.org/10.1128/JB.185.14.4248-4255.2003
  33. Wiesmann, C., W. Hengstenberg, and G. E. Schulz. 1997. Crystal structures and mechanism of $6-phospho-\beta -galactosidase$ from Lactococcus lactis. J. Mol. Biol. 269: 851-860 https://doi.org/10.1006/jmbi.1997.1084
  34. Yoo, J., K.-W. Han, H.-K. Kim, M. H. Kim, and S.-T. Kwon. 2000. Purification and characterization of a thermostable $\beta-glycosidase$ from Thermus caldophilus GK24. J. Microbiol. Biotechnol. 10: 638-642
  35. Zouhar, J., J. Vevodova, J. Marek, J. Damborsky, X. D. Su, and B. Brzobohaty. 2001. Insights into the functional architecture of the catalytic center of a maize $\beta-glucosidase$ Zm-p60.1. Plant Physiol. 127: 973-985 https://doi.org/10.1104/pp.010712