caa a22 4500 467894701 CHVBK 20180406152759.0 cr unu---uuuuu 170328e20060501xx s 000 0 eng 10.1007/s11103-005-6217-9 doi (NATIONALLICENCE)springer-10.1007/s11103-005-6217-9 Cyanide Metabolism in Higher Plants: Cyanoalanine Hydratase is a NIT4 Homolog [Elektronische Daten] [Markus Piotrowski, Julia Volmer] Cyanoalanine hydratase (E.C. 4.2.1.65) is an enzyme involved in the cyanide detoxification pathway of higher plants and catalyzes the hydrolysis of β-cyano-l-alanine to asparagine. We have isolated the enzyme from seedlings of blue lupine (Lupinus angustifolius) to obtain protein sequence information for molecular cloning. In contrast to earlier reports, extracts of blue lupine cotyledons were found also to contain cyanoalanine-nitrilase (E.C. 3.5.5.4) activity, resulting in aspartic acid production. Both activities co-elute during isolation of cyanoalanine hydratase and are co-precipitated by an antibody directed against Arabidopsis thaliana nitrilase 4 (NIT4). The isolated cyanoalanine hydratase was sequenced by nanospray-MS/MS and shown to be a homolog of Arabidopsis thaliana and Nicotiana tabacum NIT4. Full-length cDNA sequences for two NIT4 homologs from blue lupine were obtained by PCR using degenerate primers and RACE-experiments. The recombinant LaNIT4 enzymes, like Arabidopsis NIT4, hydrolyze cyanoalanine to asparagine and aspartic acid but show a much higher cyanoalanine-hydratase activity. The two nitrilase genes displayed differential but overlapping expression. Taken together these data show that the so-called ‘cyanoalanine hydratase' of plants is not a bacterial type nitrile hydratase enzyme but a nitrilase enzyme which can have a remarkably high nitrile-hydratase activity. Springer, 2006 cyanide detoxification nationallicence cyanoalanine nationallicence Lupinus angustifolius nationallicence nitrilase nationallicence nitrile hydratase nationallicence Ala(CN) : β-cyano-l-alanine nationallicence NHase : nitrile hydratase nationallicence NIT4 : nitrilase 4 nationallicence Piotrowski Markus Department of Plant Physiology, Ruhr-Universität Bochum, 44801, Bochum, Germany aut Volmer Julia Department of Plant Physiology, Ruhr-Universität Bochum, 44801, Bochum, Germany aut Plant Molecular Biology Kluwer Academic Publishers 61/1-2(2006-05-01), 111-122 0167-4412 61:1-2<111 2006 61 11103 https://doi.org/10.1007/s11103-005-6217-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11103-005-6217-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Piotrowski Markus Department of Plant Physiology, Ruhr-Universität Bochum, 44801, Bochum, Germany aut NATIONALLICENCE 700 1- Volmer Julia Department of Plant Physiology, Ruhr-Universität Bochum, 44801, Bochum, Germany aut NATIONALLICENCE 773 0- Plant Molecular Biology Kluwer Academic Publishers 61/1-2(2006-05-01), 111-122 0167-4412 61:1-2<111 2006 61 11103 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer