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.
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.
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
