Determination of aplidin, a marine-derived anticancer drug, in human plasma, whole blood and urine by liquid chromatography with electrospray ionisation tandem mass spectrometric detection.

A sensitive and highly specific liquid chromatographic method with electrospray ionisation tandem mass spectrometric detection (LC-ESI-MS/MS) is reported for the determination in human plasma, whole blood and urine of Aplidin (APL), a novel depsipeptide derived from the tunicate Aplidium albicans with a potent cytotoxic activity under investigation in clinical studies. Didemnin B was used as internal standard and, after protein precipitation with acetonitrile and liquid-liquid extraction with chloroform, APL was separated by liquid chromatography using a reversed-phase C18 column and a linear gradient of acetonitrile in water (both containing 0.5% formic acid).

Analysis of glycerophosphoinositol by liquid chromatography-electrospray ionisation tandem mass spectrometry using a beta-cyclodextrin-bonded column.

Glycerophosphoinositol (GroPIns) has been demonstrated to have important roles in many intracellular regulatory processes. GroPIns has been analysed for many years by anion-exchange HPLC after radiolabelling of cells in culture, but no method has been developed, to our knowledge, for the direct detection and quantitation of the unlabelled compound in such biological samples. Here is reported a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the direct quantitative analysis of GroPIns that can indeed be applied to cell extracts.

Liquid chromatography-electrospray mass spectrometry study of cysteine-10 S-glutathiolation in recombinant glutathione S-transferase of Ochrobactrum anthropi.

Glutathione S-transferase of Ochrobactrum anthropi (OaGST), a bacterium isolated from soils contaminated by xenobiotic pollutants, was recently purified, cloned and characterised in our laboratories. The recombinant OaGST (rOaGST), highly expressed in Escherichia coli, when purified by glutathione-affinity chromatography and then analysed by electrospray ionisation mass spectrometry (ESI-MS), has evidenced a disulphide bond with glutathione (S-glutathiolation), which was removable by reduction with 2-mercaptoethanol. Enzymatic digestion of rOaGST with endoproteinase Glu-C, followed by liquid chromatography (LC)-ESI-MS analyses of the peptide mixtures under both reducing and not reducing conditions, have shown that glutathione was covalently bound to the Cys10 residue of rOaGST.

Bacterial peptide methionine sulphoxide reductase: co-induction with glutathione S-transferase during chemical stress conditions.

Peptide methionine sulphoxide reductase (MsrA; EC 1.8.4.

Analysis of aplidine (dehydrodidemnin B), a new marine-derived depsipeptide, in rat biological fluids by liquid chromatography-tandem mass spectrometry.

Aplidine (dehydrodidemnin B) is a new marine-derived depsipeptide with a powerful cytotoxic activity, which is under early clinical investigation in Europe and in the US. In order to investigate the pharmacokinetic properties of this novel drug, an HPLC-tandem mass spectrometry method was developed for the determination of aplidine in biological samples. Didemnin B, a hydroxy analogue, was used as internal standard.

Inhibition of gelatinase A (MMP-2) by batimastat and captopril reduces tumor growth and lung metastases in mice bearing Lewis lung carcinoma.

We have examined the effects of the synthetic matrix metalloproteinase inhibitor, batimastat (BB-94) and the angiotensin-converting enzyme inhibitor, captopril, on metalloproteinase activity of murine Lewis-lung-carcinoma cells (3LL) in vitro, and on local growth and lung metastasis of the same tumor implanted intramuscularly in syngeneic C57BL/6 mice. The effect of BB-94 and captopril on the survival of the 3LL-tumor-bearing mice was also examined. Here we report that captopril treatment resulted in decreased transcription and protein levels of gelatinase A by 3LL cells.

Molecular cloning, expression and site-directed mutagenesis of glutathione S-transferase from Ochrobactrum anthropi.

The gene coding for a novel glutathione S-transferase (GST) has been isolated from the bacterium Ochrobactrum anthropi. A PCR fragment of 230 bp was obtained using oligonucleotide primers deduced from N-terminal and 'internal' sequences of the purified enzyme. The gene was obtained by screening of a genomic DNA partial library from O.