@article{RibitschKarlBirnerGruenbergeretal.2010,
  author    = {Ribitsch, D. and Karl, W. and Birner-Gruenberger, R. and Gruber, K. and Eiteljoerg, I. and Remler, P. and Wieland, S. and Siegert, Petra and Maurer, Karl-Heinz and Schwab, H.},
  title     = {C-terminal truncation of a metagenome-derived detergent protease for effective expression in E. coli},
  series = {Journal of biotechnology},
  volume    = {150},
  journal   = {Journal of biotechnology},
  number    = {3},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1873-4863 (E-Journal); 0168-1656 (Print)},
  doi       = {10.1016/j.jbiotec.2010.09.947},
  pages     = {408 -- 416},
  year      = {2010},
  abstract  = {Recently, a new alkaline protease named HP70 showing highest homology to extracellular serine proteases of Stenotrophomonas maltophilia and Xanthomonas campestris was found in the course of a metagenome screening for detergent proteases (Niehaus et al., submitted for publication). Attempts to efficiently express the enzyme in common expression hosts had failed. This study reports on the realization of overexpression in Escherichia coli after structural modification of HP70. Modelling of HP70 resulted in a two-domain structure, comprising the catalytic domain and a C-terminal domain which includes about 100 amino acids. On the basis of the modelled structure the enzyme was truncated by deletion of most of the C-terminal domain yielding HP70-C477. This structural modification allowed effective expression of active enzyme using E. coli BL21-Gold as the host. Specific activity of HP70-C477 determined with suc-l-Ala-l-Ala-l-Pro-l-Phe-p-nitroanilide as the substrate was 30 ± 5 U/mg compared to 8 ± 1 U/mg of the native enzyme. HP70-C477 was most active at 40 °C and pH 7-11; these conditions are prerequisite for a potential application as detergent enzyme. Determination of kinetic parameters at 40 °C and pH = 9.5 resulted in KM = 0.23 ± 0.01 mM and kcat = 167.5 ± 3.6 s⁻¹. MS-analysis of peptide fragments obtained from incubation of HP70 and HP70-C477 with insulin B indicated that the C-terminal domain influences the cleavage preferences of the enzyme. Washing experiments confirmed the high potential of HP70-C477 as detergent protease.},
  language  = {en}
}
@article{RibitschHeumannTrotschaetal.2011,
  author    = {Ribitsch, D. and Heumann, S. and Trotscha, E. and Herrero Acero, E. and Greimel, K. and Leber, R. and Birger-Gruenberger, R. and Deller, S. and Eiteljoerg, I. and Remler, P. and Weber, Th. and Siegert, Petra and Maurer, Karl-Heinz and Donelli, I. and Freddi, G. and Schwab, H. and Guebitz, G. M.},
  title     = {Hydrolysis of polyethyleneterephthalate by p-nitrobenzylesterase from Bacillus subtilis},
  series = {Biotechnology progress},
  volume    = {Vol. 27},
  journal   = {Biotechnology progress},
  number    = {Iss. 4},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {1520-6033 (E-Journal); 8756-7938 (Print)},
  pages     = {951 -- 960},
  year      = {2011},
  language  = {en}
}
@article{RibitschHeumannKarletal.2012,
  author    = {Ribitsch, D. and Heumann, S. and Karl, W. and Gerlach, J. and Leber, R. and Birner-Gruenberger, R. and Gruber, K. and Eiteljoerg, I. and Remler, P. and Siegert, Petra and Lange, J. and Maurer, Karl-Heinz and Berg, G. and Guebitz, G. M. and Schwab, H.},
  title     = {Extracellular serine proteases from Stenotrophomonas maltophilia: Screening, isolation and heterologous expression in E. coli},
  series = {Journal of biotechnology},
  volume    = {157},
  journal   = {Journal of biotechnology},
  number    = {1},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1873-4863 (E-Journal); 0168-1656 (Print)},
  doi       = {10.1016/j.jbiotec.2011.09.025},
  pages     = {140 -- 147},
  year      = {2012},
  abstract  = {A large strain collection comprising antagonistic bacteria was screened for novel detergent proteases. Several strains displayed protease activity on agar plates containing skim milk but were inactive in liquid media. Encapsulation of cells in alginate beads induced protease production. Stenotrophomonas maltophilia emerged as best performer under washing conditions. For identification of wash-active proteases, four extracellular serine proteases called StmPr1, StmPr2, StmPr3 and StmPr4 were cloned. StmPr2 and StmPr4 were sufficiently overexpressed in E. coli. Expression of StmPr1 and StmPr3 resulted in unprocessed, insoluble protein. Truncation of most of the C-terminal domain which has been identified by enzyme modeling succeeded in expression of soluble, active StmPr1 but failed in case of StmPr3. From laundry application tests StmPr2 turned out to be a highly wash-active protease at 45 °C. Specific activity of StmPr2 determined with suc-l-Ala-l-Ala-l-Pro-l-Phe-p-nitroanilide as the substrate was 17 ± 2 U/mg. In addition we determined the kinetic parameters and cleavage preferences of protease StmPr2.},
  language  = {en}
}