1.beta-Ureidopropionase deficiency: a novel inborn error of metabolism discovered using NMR spectroscopy on urine.
Moolenaar SH1, Göhlich-Ratmann G, Engelke UF, Spraul M, Humpfer E, Dvortsak P, Voit T, Hoffmann GF, Bräutigam C, van Kuilenburg AB, van Gennip A, Vreken P, Wevers RA. Magn Reson Med. 2001 Nov;46(5):1014-7.
In this work, NMR investigations that led to the discovery of a new inborn error of metabolism, beta-ureidopropionase (UP) deficiency, are reported. 1D (1)H-NMR experiments were performed using a patient's urine. 3-Ureidopropionic acid was observed in elevated concentrations in the urine spectrum. A 1D (1)H-(1)H total correlation spectroscopy (TOCSY) and two heteronuclear 2D NMR techniques (heteronuclear multiple bond correlation (HMBC) and heteronuclear single-quantum correlation (HSQC)) were used to identify the molecular structure of the compound that caused an unknown doublet resonance at 1.13 ppm. Combining the information from the various NMR spectra, this resonance could be assigned to 3-ureidoisobutyric acid. These observations suggested a deficiency of UP. With 1D (1)H-NMR spectroscopy, UP deficiency can be easily diagnosed. The (1)H-NMR spectrum can also be used to diagnose patients suffering from other inborn errors of metabolism in the pyrimidine degradation pathway.
2.Discovery of safety biomarkers for atorvastatin in rat urine using mass spectrometry based metabolomics combined with global and targeted approach.
Kumar BS1, Lee YJ, Yi HJ, Chung BC, Jung BH. Anal Chim Acta. 2010 Feb 19;661(1):47-59. doi: 10.1016/j.aca.2009.11.063. Epub 2009 Dec 4.
In order to develop a safety biomarker for atorvastatin, this drug was orally administrated to hyperlipidemic rats, and a metabolomic study was performed. Atorvastatin was given in doses of either 70 mg kg(-1) day(-1) or 250 mg kg(-1) day(-1) for a period of 7 days (n=4 for each group). To evaluate any abnormal effects of the drug, physiological and plasma biochemical parameters were measured and histopathological tests were carried out. Safety biomarkers were derived by comparing these parameters and using both global and targeted metabolic profiling. Global metabolic profiling was performed using liquid chromatography/time of flight/mass spectrometry (LC/TOF/MS) with multivariate data analysis. Several safety biomarker candidates that included various steroids and amino acids were discovered as a result of global metabolic profiling, and they were also confirmed by targeted metabolic profiling using gas chromatography/mass spectrometry (GC/MS) and capillary electrophoresis/mass spectrometry (CE/MS).
3.Pig kidney legumain: an asparaginyl endopeptidase with restricted specificity.
Dando PM1, Fortunato M, Smith L, Knight CG, McKendrick JE, Barrett AJ. Biochem J. 1999 May 1;339 ( Pt 3):743-9.
Legumain was recently discovered as a lysosomal endopeptidase in mammals [Chen, Dando, Rawlings, Brown, Young, Stevens, Hewitt, Watts and Barrett (1997) J. Biol. Chem. 272, 8090-8098], having been known previously only from plants and invertebrates. It has been shown to play a key role in processing of the C fragment of tetanus toxin for presentation by the MHC class-II system [Manoury, Hewitt, Morrice, Dando, Barrett and Watts (1998) Nature (London) 396, 695-699]. We examine here the specificity of the enzyme from pig kidney by use of protein, oligopeptide and synthetic arylamide substrates, all determinations being made at pH 5.8. In proteins, only about one in ten of the asparaginyl bonds were hydrolysed, and these were mostly predicted to be located at turns on the protein surface. Bonds that were not cleaved in tetanus toxin were cleaved when presented in oligopeptides, sometimes faster than an equivalent oligopeptide based on a bond that was cleaved in the protein.
4.The intramolecular cyclization 2-Iodo-3-ureidopropionic acid.
Buehler M, Sander EG. Biochem Biophys Res Commun. 1978 May 15;82(1):196-202.
