Pivotal role for two electron reduction in 2,3-dimethoxy-1,4-naphthoquinone and 2-methyl-1,4-naphthoquinone metabolism and kinetics in vivo that prevents liver redox stress.

2,3-dimethoxy-1,4-naphthoquinone (CAS-RN 6959-96-3) (DMNQ) and 2-methyl-1,4-naphthoquinone (CAS-RN 58-27-5) (MNQ:menadione) are effective one electron redox cycling chemicals in vitro. In addition, in vitro MNQ forms a thioether conjugate with glutathione by nucleophilic attack at the third carbon. In contrast, here we demonstrate that in vivo the major metabolic route is directly to the dihydronaphthoquinone for both DMNQ and MNQ followed by conjugation to mono- and di-glucuronides and sulfate.

Proteomic analysis of rat kidney cortex following treatment with gentamicin.

The regionally specific structure and function of the kidney renders it susceptible to toxic exposure. To characterize these changes at the proteome level, we have investigated the effects on protein expression following treatment with gentamicin. The more than 20 proteins identified were involved in the citric acid cycle, gluconeogenesis, fatty acid synthesis, and transport or cellular stress responses.

Use of proteomic methodology for the characterization of human milk fat globular membrane proteins.

Characterization of the major human milk fat globular membrane proteins was carried out using proteomic techniques comprising two-dimensional polyacrylamide gel electrophoresis, followed by in situ PNGase F and trypsin digestion. Matrix-assisted laser desorption/ionization quadrupole time-of-flight and electrospray ionization mass spectrometry identified seven major protein components: alpha-lactalbumin, lysozyme precursor, beta-casein, clusterin, lactotransferrin, polymeric immunoglobulin receptor precursor, and human milk fat globule EGF-factor 8 protein. Sequence information on the protein-associated glycans was determined by matrix-assisted laser desorption-ionization quadrupole time-of-flight hybrid mass spectrometry.