Development of a new nano arginase HPLC capillary column for the fast screening of arginase inhibitors and evaluation of their binding affinity

New liquid chromatography columns for highlighting the interaction of ligand candidates with humic acid

Humic acid was the main compound in soil and reduced the availability of some organic compounds in soils. In this work, humic acid was immobilized for the first time on a homemade neutravidin poly(glycidyl methacrylate-co-ethylene dimethacrylate) capillary column with a 20 μm i.d. for the screening of potential ligands to humic acid and the evaluation of their molecular recognition mechanism. This homemade humic acid column enabling it to work at very low backpressure (0.60 MPa at 20 nl/min flow rate), had a long lifetime, excellent repeatability, and negligible non-specific binding sites. The performance of this affinity humic acid column was demonstrated by the evaluation of recognition assay for a series of known ligands of humic acid (a series of rodenticide molecules) which is the heart of the fragment-based drug design. In addition, this column was used successfully for highlighting the binding mechanism to humic acid of the severe acute respiratory syndrome coronavirus-2-spike protein. As well this new humic acid miniaturized liquid chromatography column developed in this work could be used in the feature for another solute molecule-humic acid binding studies or for a separative mode.

Functionalized monolithic columns: Recent advancements and their applications for high-efficiency separation and enrichment in food and medicine

The chromatographic column is the core of a high-performance liquid chromatography (HPLC) system, and must have excellent separation efficiency and selectivity. Therefore, functional modification materials for monolithic columns have been rapidly developed. This study is a systematic review of the recently reported functionalized monolithic columns. In particular, the study reviews the types of functional monomers under different modification conditions, as well as the separation and detection techniques combined with chromatography, and their development prospects. In addition, the applications of functionalized monolithic columns in food analysis, biomedicine, and the analysis of active ingredient of Chinese herbal medicines in recent years are also discussed. Also reviewed are the functionalized monolithic columns for qualitative and quantitative analysis. It provided a reference for further development and application of organic polymer monolithic columns.

ACE2 and SARS-CoV-2-Main Protease Capillary Columns for Affinity Chromatography: Testimony of the Binding of Dexamethasone and its Carbon Nanotube Nanovector

In this paper, each of the two following proteins, the angiotensin-converting enzyme 2 (ACE2) and the Main protease (Main pro) of the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) were grafted for the first time on homemade neutravidin poly(GMA-co-EDMA) capillary columns for the research of their ligands. The effect of the column diameter on the quantity of immobilized biotinylated protein was studied. For a capillary length of 40 mm, when its internal diameter varied from 75 to 25 μm, the grafted quantity of ACE2 decreased by 85% (from 1.50 to 0.24 μg). Among all the studied ligands, a particular vigilance has been given for dexamethasone, a widely used molecule today for adult patients hospitalized with SARS-CoV-2. Competition experiments were performed with SARS-CoV-2 Receptor Binding Domain used as reference molecule with the ACE2 affinity column to assess the orthosteric binding site of dexamethasone (Dex) on ACE2. This ligand was then immobilized on Multiwall Carbon Nanotubes (Dex/MWCNT). By comparison of the normalized breakthrough curves measured for Dex and Dex/MWCNT on both the ACE2 and Main pro affinity columns, it was showed for the first time that nanovectorisation of Dex with MWCNT enhanced and stabilized its binding to both ACE2 and Main pro. This last result reinforced the use of Dex and the interest of MWCNT for boosting immune health against COVID 19.