caa a22 4500 475744586 CHVBK 20180406123509.0 cr unu---uuuuu 170329e20000201xx s 000 0 eng 10.1023/A:1007082516503 doi (NATIONALLICENCE)springer-10.1023/A:1007082516503 Photoreversible Modulators of Escherichia coli β-Galactosidase. 1-Benzoyl-1-cyano-2-(4,5-dimethoxy-2-nitrophenyl)-ethene and 1,1-Dicyano-2-(4,5-dimethoxy-2-nitrophenyl)-ethene [Elektronische Daten] [Rachel Golan, Uri Zehavi, Michael Naim, Abraham Patchornik, Patricia Smirnoff, Mina Herchman] β-Galactosidase (EC 3.2.1.23) is known to be inhibited by some thiol reagents. 1-Benzoyl-1-cyano-2-(4,5-dimethoxy-2-nitrophenyl)-ethene (1) was shown to be an irreversible inhibitor, while 1, 1-dicyano-2-(4,5-dimethoxy-2-nitrophenyl)-ethene (2) was demonstrated as a positive irreversible modulator causing a rise of up to 186% in β-galactosidase activity. Compound 2 is, however, an irreversible inhibitor of the cysteine proteinase papain (preceding paper). Kinetic values of β-galactosidase at pH 8.3 with o-nitrophenyl β-D-galactopyranoside (ONPG) as the substrate and for compounds 1 and 2 were determined and in view of model experiments, it was assumed that both compounds possibly reacted with the thiol side chain of Cys in the active site inducing allosteric changes in the enzyme. Since the enzyme, modified by compound 1 or 2, was a 2-nitrobenzyl derivative, near-UV irradiation resulted in a recovery of up to 91% and a reduction of the enzyme's activity to 90%, respectively. Plenum Publishing Corporation, 2000 β-Galactosidase nationallicence photoreversible inhibitor nationallicence photoreversible modulator nationallicence 1-benzoyl-1-cyano-2-(4,5-dimethoxy-2-nitrophenyl)-ethene nationallicence 1,1-dicyano-2-(4,5-dimethoxy-2-nitrophenyl)-ethene nationallicence Golan Rachel Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, P.O. Box 12, 76100, Rehovot, Israel aut Zehavi Uri Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, P.O. Box 12, 76100, Rehovot, Israel aut Naim Michael Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, P.O. Box 12, 76100, Rehovot, Israel aut Patchornik Abraham Department of Organic Chemistry, The Weizmann Institute, of Science, 76100, Rehovot, Israel aut Smirnoff Patricia Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, P.O. Box 12, 76100, Rehovot, Israel aut Herchman Mina Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, P.O. Box 12, 76100, Rehovot, Israel aut Journal of Protein Chemistry Kluwer Academic Publishers-Plenum Publishers 19/2(2000-02-01), 123-128 0277-8033 19:2<123 2000 19 10930 https://doi.org/10.1023/A:1007082516503 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1007082516503 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Golan Rachel Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, P.O. Box 12, 76100, Rehovot, Israel aut NATIONALLICENCE 700 1- Zehavi Uri Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, P.O. Box 12, 76100, Rehovot, Israel aut NATIONALLICENCE 700 1- Naim Michael Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, P.O. Box 12, 76100, Rehovot, Israel aut NATIONALLICENCE 700 1- Patchornik Abraham Department of Organic Chemistry, The Weizmann Institute, of Science, 76100, Rehovot, Israel aut NATIONALLICENCE 700 1- Smirnoff Patricia Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, P.O. Box 12, 76100, Rehovot, Israel aut NATIONALLICENCE 700 1- Herchman Mina Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, P.O. Box 12, 76100, Rehovot, Israel aut NATIONALLICENCE 773 0- Journal of Protein Chemistry Kluwer Academic Publishers-Plenum Publishers 19/2(2000-02-01), 123-128 0277-8033 19:2<123 2000 19 10930 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer