The reaction of protected 4,5-diiodoimidazoles with (PhMe2CCH2)2CuLi regioselectively provides 5-cuprated imidazoles, which readily react with various electrophiles furnishing functionalized imidazoles in good yields; remarkably, these resulting mono-iodoimidazoles undergo again an iodine-copper exchange reaction in the presence of sensitive functional groups, like an aldehyde or a ketone.

A simple method is described for the separation and quantification of the subunits of GSH transferases present in rat tissue extracts. This method, involving GSH-agarose affinity chromatography followed by reverse-phase h.p.l.c., is rapid and sufficiently sensitive to measure 5 micrograms of each subunit in a mixture. Examples are given of its application to extracts of rat kidney, adrenal, tes...

A model for protein synthesis is proposed in which the donor for the peptide elongation reaction is peptidyl-5S RNA. Space-filling models show that peptide bond formation between peptidyl-5S RNA and aminoacyl-tRNA is eminently feasible from a stereochemical point of view. The peptide is transferred to 5S RNA, while at the same time the deacylated tRNA is exchanged by a new aminoacyl-tRNA accept...

Homogenous preparations of XenB of Pseudomonas putida, pentaerythritol tetranitrate reductase of Enterobacter cloacae, and N-ethylmaleimide reductase of Escherichia coli, all type II hydride transferases of the Old Yellow Enzyme family of flavoproteins, are shown to reduce the polynitroaromatic compound 2,4,6-trinitrotoluene (TNT). The reduction of this compound yields hydroxylaminodinitrotolue...

Glutathione S-transferases constitute a very important family of biotransformation enzymes, which catalyse the conjugation of glutathione to a broad spectrum of xenobiotics. In this study, cytosolic glutathione S-transferases enzymes were purified from lamprey (Petromyzon marinus) liver, using an affinity chromatography method. Enzymatic activity was determined towards 1-chloro-2,4-dinitrobenze...

immunochemically detectable protein, and catalytic activity in different liver samples (Distlerath et al., 1985; Shimada et al., 1986; Umbenhauer et al., 1986). However, rat P-450,,,., , the orthologue of P-450,,, and its activities are well correlated with levels of the 2000 nucleotide mRNA(s) coding for the protein (Churchill et al., 1987); this regulatory model does not seem appropriate for ...

The glutathione transferases (GSTs) are one of the most important families of detoxifying enzymes in nature. The classic activity of the GSTs is conjugation of compounds with electrophilic centers to the tripeptide glutathione (GSH), but many other activities are now associated with GSTs, including steroid and leukotriene biosynthesis, peroxide degradation, double-bond cis-trans isomerization, ...