Application of thiophilic chromatography to deplete serum immunoglobulins in sample preparation for bidimensional electrophoresis

Depletion of high-abundance flavonoids by metal complexation and identification of low-abundance flavonoids in Scutellaria baicalensis Georgi

The complexation of metal cations and flavonoids with 5-hydroxyl or ortho-hydroxyl groups was successfully used for high-abundance flavone depletion from a botanical extract in this study. Due to their structural differences, five of the most highly abundant constituents, baicalin, wogonoside, baicalein, wogonin and oroxylin A, were successfully depleted from the ethanol extract of Radix Scutellariae. The depletion rates were approximately 99%, 85%, 99%, 70% and 76%, respectively. The recoveries of low-abundance constituents were very strong (approximately 70-100%). The efficiency of the low-abundance compounds' identification by high performance liquid chromatography electrospray tandem mass spectrometry (HPLC ESI MS/MS) was remarkable after the high-abundance constituents were removed. The number of compounds identified from the HPLC MS/MS data was 250% greater than the number of compounds identified in the untreated total extract. One hundred seventeen flavonoids were identified in the ethanol extract of Radix Scutellariae using this method, which was much greater than the number identified in previous studies without high-abundance constituent depletion. Among them, 13 sulphated flavonoids were identified. These low-abundance sulphated flavonoids can barely be detected in untreated total extracts. To the best of our knowledge, this is the first reported evidence that sulphated flavonoids have been identified from Radix Scutellariae. This method will facilitate the removal of high-abundance flavonoids and the identification of low-abundance compounds in botanical extracts.

Simultaneous depletion of immunoglobulin G and albumin from human plasma using novel monolithic cryogel columns

In this study, we aimed to develop an alternative matrix able to deplete the albumin (Alb) and immunoglobulin G (IgG) from blood plasma simultaneously to prepare plasma samples for large-scale applications of blood-related proteomics. As a first step, nano-protein A nanoparticles (nanoProA) were prepared and characterized. Subsequently, cibacron blue F3GA (CB) was immobilized onto the nanoProA's to enhance their specific affinity for Alb molecules. Finally, both nanoparticles, specifically, nanoProA and CB-nanoProA, were separately embedded into cryogel structures to combine advantages of the nanoparticles with those of the cryogels. The protein adsorption was optimized using aqueous Alb and IgG solutions separately. Subsequently, competitive protein adsorption was performed using a protein mixture prepared with Alb and IgG adhering to their plasma protein ratios. Because of the CB-immobilization, the Alb depletion performance of the cryogels increased whereas the IgG depleting performance decreased. Using the nanoProA, embedded cryogel removed 99.3% of the IgG, while using the CB-nanoProA embedded cryogel removed 97.5% of the Alb content. The simultaneous depletion performances of the cryogels for Alb and IgG were characterized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In this study, the monolithic cryogel-based adsorbents were classified as an alternative matrix to prepare plasma samples for proteomics applications at the preparative scale.

Application for proteomic techniques in studying osteoarthritis: a review

After the genomic era, proteomic corresponds to a wide variety of techniques that study the protein content of cells, tissue, or organism and that allow the isolation of protein of interest. It offers the choice between gel-based and gel-free methods or shotgun proteomics. Applications of proteomic technology may concern three principal objectives in several biomedical or clinical domains of research as in osteoarthritis: (i) to understand the physiopathology or underlying mechanisms leading to a disease or associated with a particular model, (ii), to find disease-specific biomarker, and (iii) to identify new therapeutic targets. This review aimed at gathering most of the data regarding the proteomic techniques and their applications to osteoarthritis research. It also reported technical limitations and solutions, as for example for sample preparation. Proteomics open wide perspectives in biochemical research but many technical matters still remain to be solved.