119643-82-2Relevant articles and documents
An unusually cold active nitroreductase for prodrug activations
?elik, Ayhan,Yeti?, Gülden
, p. 3540 - 3550 (2012)
A set of PCR primers based on the genome sequence were used to clone a gene encoding a hypothetical nitroreductases (named as Ssap-NtrB) from uropathogenic staphylococcus, Staphylococcus saprophyticus strain ATCC 15305, an oxygen insensitive flavoenzyme. Activity studies of the translation product revealed that the nitroreductase catalyses two electron reduction of a nitroaromatic drug of nitrofurazone (NFZ), cancer prodrugs of CB1954 and SN23862 at optimum temperature of 20 °C together with retaining its maximum activity considerably at 3 °C. The required electrons for such reduction could be supplied by either NADH or NADPH with a small preference for the latter. The gene was engineered for heterologous expression in Escherichia coli, and conditions were found in which the enzyme was produced in a mostly soluble form. The recombinant enzyme was purified to homogeneity and physical, spectral and catalytical properties were determined. The findings lead us to propose that Ssap-NtrB represents a novel nitro reductase with an unusual cold active property, which has not been described previously for prodrug activating enzymes of nitroreductases.
Binding of the anticancer prodrug CB1954 to the activating enzyme NQO2 revealed by the crystal structure of their complex
AbuKhader, Majed,Heap, John,De Matteis, Cristina,Kellam, Barrie,Doughty, Stephen W.,Minton, Nigel,Paoli, Massimo
, p. 7714 - 7719 (2005)
CB1954 is an attractive prodrug for directed-enzyme prodrug therapy (DEPT) and a conventional prodrug against tumors in which the enzyme NQO2 is highly expressed. We have determined the crystal structure of the NQO2-CB1954 complex to 2.0 ? resolution. The binding of the prodrug is governed by hydrophobic forces, while two key electrostatic contacts determine the specific orientation of the ligand. The structure also reveals an unfavorable interaction, therefore suggesting possible avenues for DEPT-tailored engineering studies.
Time dependent HPLC analysis of the product ratio of enzymatically reduced prodrug CB1954 by a modified and immobilised nitroreductase
Ball, Patrick,Thompson, Emma,Anderson, Simon,Gwenin, Vanessa,Gwenin, Chris
, p. 217 - 224 (2019)
Directed enzyme prodrug therapy is a chemotherapy strategy that utilises prodrug-activating enzymes to activate prodrugs at the tumour location, thus reducing off-target effects. The most commonly investigated enzyme for use with the CB1954 prodrug is the NfnB nitroreductase from E. coli. Literature states that CB1954 is reduced by NfnB at the 2- or 4-position at a 1:1 ratio; deviation from this ratio has been observed in the literature, but not further investigated. The kinetic parameters for the genetically-modified enzymes; NfnB-his, NfnB-cys and AuNP-NfnB-cys were assessed and HPLC analysis was used to determine the hydroxylamine product ratios formed when reacted with CB1954. Time-dependent HPLC studies were carried out to assess how this ratio changes over time. It was shown that the hydroxylamine ratio formed by the reduction of CB1954 by a nitroreductase changes over time and that this change in ratio relates directly to the kinetics of the reaction. Thus, the hydroxylamine ratio measured using HPLC at a given time point was not a true indication of the preference of the nitroreductase enzymes during catalysis. These results question how nitroreductases are evaluated in terms of the hydroxylamine ratio and it is suspected that this phenomenon may also apply to other enzyme/prodrug combinations.
USE OF ALPHA-HYDROXY CARBONYL COMPOUNDS AS REDUCING AGENTS
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Page/Page column 63-65, (2008/06/13)
There is provided the use as reducing agents of alpha-hydroxycarbonyl compounds capable of forming cyclic dimers. There is also provided corresponding methods of reducing reducible compounds, particularly reduction-activated prodrugs . Examples of the alp
Reductive chemistry of the novel hypoxia-selective cytotoxin 5-[N,N- bis(2-chloroethyl)amino]-2,4-dinitrobenzamide
Palmer,Van Zijl,Denny,Wilson
, p. 1229 - 1241 (2007/10/02)
5-[N,N-Bis(2-chloroethyl)amino]-2,4-dinitrobenzamide (1; SN 23862) is a novel bioreductive drug whose selective toxicity for hypoxic cells appears due to oxygen-inhibited enzymatic reduction of one of the nitro groups to the corresponding amine or hydroxy
Catalytic properties of NAD(P)H:quinone acceptor oxidoreductase: Study involving mouse, rat, human, and mouse-rat chimeric enzymes
Chen, Shiuan,Knox, Richard,Lewis, Alexander D.,Friedlos, Frank,Workman, Paul,Deng, Paulis S. K.,Fung, Maisie,Ebenstein, Donna,Wu, Kebin,Tsai, Ta-Ming
, p. 934 - 939 (2007/10/03)
NAD(P)H:quinone acceptor oxidoreductase (quinone reductase) (DT- diaphorase, EC 1.6.99.2) is involved in the process of reductive activation of cytotoxic antitumor quinones and nitrobenzenes. In this study, we initially examined the relative abilities of mouse, rat, and human quinone reductases to reduce two prodrugs, CB 1954 [5-(aziridin-1-yl)-2,4- dinitrobenzamide] and EO9 [5-(1-aziridinyl)-3-(hydroxymethyl)-2-(3-hydroxy- 1-propenyl)-1-methyl-1H-indole-4,7-dione]. By using Escherichia coli- expressed quinone reductases and evaluating them under identical conditions, we confirmed previous findings showing that the human enzyme is not as effective as the rat enzyme in reducing CB 1954 and EO9, although the two enzymes have similar NAD(P)H-menadione reductase activities. Interestingly, although the amino acid sequence of mouse quinone reductase is more homologous to that of the rat enzyme, we found that the mouse enzyme behaves similarly to the human enzyme in its ability to reduce these compounds and to generate drug-induced DNA damage. To determine the region of quinone reductase that is responsible for the catalytic differences, two mouse-rat chimeric enzymes were generated. MR-P, a chimeric enzyme that has mouse amino-terminal and rat carboxyl-terminal segments of quinone reductase, was shown to have catalytic properties resembling those of rat quinone reductase, and RM-P, a chimeric enzyme that has rat amino-terminal and mouse carboxyl- terminal segments of quinone reductase, was shown to have catalytic properties resembling those of mouse quinone reductase. In addition, MR-P and RM-P were found to be inhibited by flavones with K(i) values similar to those for rat and mouse quinone reductases, respectively. Based on these results, we propose that the carboxyl-terminal portion of the enzyme plays an important role in the reduction of cytotoxic drugs and the binding of flavones.