Analytical methods for selenium (Se) speciation were developed using high-performance liquid chromatography (HPLC) coupled to either inductively coupled plasma mass spectrometry (ICP–MS) or electrospray ionization tandem mass spectrometry (ESI–MS/MS). Separations of selenomethionine (Se-Met) and selenocysteine (Se-(Cys)2) with favorable peak shape and resolution were obtained by both HPLC-ICP-MS and HPLC–ESI–MS/MS. Both methods achieved low limits of detection, high sensitivity and favorable stability. With HPLC–ESI–MS/MS, signal suppression was observed when complex matrix was co-eluted, but excellent structural characterization was still achieved. Thus, HPLC-ICP-MS is better for the detection of Se species, and HPLC–ESI–MS/MS is essential for molecular identification and confirmation. A water-soluble selenoprotein from purified M. anguillicaudatus muscle tissue was analyzed by the two complementary systems (HPLC-ICP-MS and HPLC–ESI–MS/MS) with high sensitivity and accuracy. The results demonstrated that Se-Met was the predominant selenoamino acid in the purified selenoprotein from M. anguillicaudatus muscle tissue, and the concentration of Se-Met in the selenoprotein was 6.280 mg/kg (dry mass). In addition, in HPLC-ICP-MS, an unknown Se-containing compound with similar polarity to Se-(Cys)2 was discovered. Using complementary data from HPLC–ESI–MS/MS, it was determined that this unknown Se-containing compound was not Se(Cys)2.
Endothelial nitric oxide synthase polymorphism G298T in association with oxidative DNA damage in coronary atherosclerosis
Content Type Journal Article
Category Research Note
RAJESH G. KUMAR, Department of Genetics, Osmania Univers ... more
A micropropagation protocol was developed for multiplication of seedless lemon (Citrus limon L. cv. Kaghzi Kalan) using nodal explants. The maximum shoot regeneration was observed on low level of BAP (0.1 mg l−1) or kinetin (0.5 mg l−1). BA was recorded to be better than kinetin in terms of ... more
The objective of this study was to evaluate the activity, kinetic behavior, and thermal inactivation kinetics of peroxidase (POD) in aqueous extracts from two kinds of milk ripe stage corn, sweet corn and waxy corn. Optimum activities using guaiacol as the hydrogen donor were obtained for s ... more