Erratum to: Purification and characterization of heterologously expressed nitrilases from filamentous fungi

Abstract

Two works cited in the previous article (Kaplan et al. 2006, 2011) were corrected (Kaplan et al. 2013a) or retracted (Kaplan et al. 2013b). The reason was the falsity of data (N-terminal aa sequence and theMALDI-TOF analysis) by KBwhose ethics of scientific workwas examined in 2012 by the Ethics Commission of the Charles University in Prague and the Institute of Microbiology of the Academy of Sciences of the Czech Republic. The Commission found scientific misconduct of KB in several cases. Therefore, we wish to correct the following parts of the previous article: Introduction: “The nitrilase studied by us in Aspergillus niger K10 was the first fungal nitrilase to be purified from both its native... and heterologous producer...” Actually, the enzymes purified from the native and heterologous producer were different. The enzyme natively expressed in this strain was purified and characterised (Kaplan et al. 2006) and its partial aa sequence was recently published (Kaplan et al. 2013a). The recombinant enzyme was recently examined for its substrate specificity in whole cells (Kaplan et al. 2013c), and was found to be a cyanide hydratase with a significant nitrilase activity. Materials and methods, Nitrilase expression: Construction of plasmid pOK101 referred toKaplan et al. 2011 (retracted article). Therefore, we wish to describe this method here: To construct plasmid pOK101, NdeI-HindIII fragment of the PCR product amplified from cDNA of Aspergillus niger K10 (forward primer 5′-GCC ATATGG CAC CMG TCT TRA AGA AGTACA A3′, M=A or C; R=A or G, and reverse primer, 5′-GCA AGC TTT TAC TAG TTC TCC GAATCC ACG GT-3′) was ligated into vector pET-30a(+) (Novagen). Results, Variability of fungal nitrilases: The statement that in the nitrilase fromA . niger K10 “both its amino acid sequence and its biochemical properties have been already known” referred to Kaplan et al. 2011 (retracted article). For substrate specificity of this enzyme please refer to Kaplan et al. 2013c (see also above). Results, Nitrilase in Aspergillus niger K10: The hypothesis that the difference of substrate specificities in the natively expressed and the recombinant enzymes were caused by misfolding of the latter referred to Kaplan et al. 2011 (retracted article). Actually, the two enzymes were different in terms of their primary structure (see above). The online version of the original article can be found at http://dx.doi.org/ 10.1007/s00253-011-3525-7.