A simple, fast, and cost-effective LC-MS/MS method for quantification of rifampicin in human plasma was developed and fully validated. The plasma samples containing rifampicin and isotopically labelled internal standard rifampicin D8, were cleaned up using a Captiva ND Lipids filtration plate. Chromatographic separation was achieved on an 1290 Infinity liquid chromatograph coupled to 6460 Triple Quadrupole operated in positive mode on a core-shell Kinetex C18 column (50 × 2.1 mm, 2.6 m) by gradient elution using 0.1% formic acid in water and acetonitrile as a mobile phase. The proposed method is the fastest method published by now, both in terms of sample preparation (approximately one minute per sample) and chromatographic analysis (total run time 2.4 min). Another key benefit is the outstanding sensitivity and wide analytical range (5-40000 g/L) with good linearity, accuracy, and precision. The method showed almost complete recovery (92%) and absence of any significant matrix effect as demonstrated by uniform responses from QC samples prepared in blood plasma from 6 volunteers (RSD <5%). The proposed method was successfully applied to rifampicin quantification in 340 patients' plasma samples, thus demonstrating its suitability for both therapeutic drug monitoring and pharmacokinetic analysis.
Introduction: Protein acetylation is an extensively investigated post-translational modification (PTM). In addition to lysine acetylation, three new types of lysine acylations characterized by the presence of an acidic carboxylic group have been recently identified and validated. These included lysine malonylation (Kmal), lysine succinylation (Ksucc) and lysine glutarylation (Kglu).
Proteomics, Lipidomics and Metabolomics Core Facility, School of Life Sciences, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia.
Introduction: The identification of effective, selective biomarkers and therapeutics is dependent on truly deep, comprehensive analysis of proteomes at the proteoform level.
Methods: Bovine serum albumin (BSA) isolated by two different protocols, cold ethanol fractionation and heat shock fractionation, was resolved and identified using Integrative Top-down Proteomics, the tight coupling of two-dimensional gel electrophoresis (2DE) with liquid chromatography and tandem mass spectrometry (LC-MS/MS).
Results And Discussion: Numerous proteoforms were identified in both "purified" samples, across a broad range of isoelectric points and molecular weights.
Background: Glioblastoma (GB) is the stage IV of glioma and mesenchymal GB represents the most common and malignant subtype characterized with elevated expression of a mesenchymal marker YKL-40 and resistance to immune drug therapy. Here, we determined if YKL-40 regulates kynurenine (Kyn) pathway (KP) metabolism that contributes to establishing an immune suppressive microenvironment in GB.
Methods: Tumor cells expressing YKL-40 from GB patients were isolated and activated cellular metabolisms were identified via gene microarray analysis.
A previously developed algorithm for the preliminary identification of protein proteoforms associated with post-translational modifications (PTMs) based on 2D electrophoresis data (DOI: 10.18097/BMCRM00191) has been used in this study for analysis of experimental data obtained using mice and reported in two papers by different authors. The authors of the first paper identified 8 groups of spots on 2D electrophoretic maps corresponding to 8 proteins with at least two unconcretised proteoforms.
Objective: Glucose metabolism is the main way in which cells obtain energy during exercise and plays an important role in exercise. The purpose of this study was to explore the changes in the expression of glucose metabolism-related proteins in urine after running, and finally applied to the monitoring of running training.
Methods: Urine samples were collected before and after running, and urine proteomics information was collected to explore the expression of proteins in the urine using LC-MS/MS in DDA mode and DIA mode.
