Improved Protein Coverage in Bottom-Up Proteomes Analysis Using Fluoroalcohol-Mediated Supramolecular Biphasic Systems With Mixed Amphiphiles for Sample Extraction, Fractionation, and Enrichment.

A new class of supramolecular biphasic systems containing fluoroalcohol-induced coacervates (FAiC) provides concomitant fractionation of complex protein mixtures, high solubilizing power for extraction of various types of proteins, especially those with high hydrophobicity (such as membrane proteins), and enrichment of low-abundance proteins. Subsequently, the use of FAiC biphasic systems (BPS) in the bottom-up proteomics workflow resulted in significantly higher coverage for the whole proteome, various subproteomes, especially those embedded or associated with membranes, post-translationally modified proteins, and low-abundance proteins (LAPs) as compared to the conventional methodologies. In this work, we used a new type of FAiC-BPS composed of mixed amphiphiles, a zwitterionic surfactant 3-(,-dimethylmyristyl ammonia) propane sulfonate (DMMAPS), a quaternary ammonium salt (QUATS), and hexafluoroisopropanol (HFIP) as the coacervator for extraction, fractionation, and enrichment of yeast proteome in bottom-up proteomics.

Enhancing the selectivity of polar hydrophilic analytes with a low concentration of barium ions in the mobile phase using geopolymers and silica supports.

Charged analytes such as organic sulfonic acids, sulfates, carboxylates, and phosphates are often analyzed by hydrophilic interaction liquid chromatography (HILIC). In many cases, these analytes do not show any selectivity and elute near the dead time using the conventional acetonitrile-ammonium acetate buffers. In this work, we introduce a powerful selectivity enhancing technique by using a trace amount of Ba ion in the mobile phase as a general approach for HILIC with UV-Vis detection.

Synthetic aluminosilicate based geopolymers - Second generation geopolymer HPLC stationary phases.

A survey of existing stationary phases classified by the United States Pharmacopeia reveals that 120 groups of chromatographic supports mostly utilize silica-silane chemistry, polymeric materials along with some niche metal oxides. In this work, the synthesis and characterization of transition-metal free geopolymers as a new class of stationary phases for hydrophilic interaction liquid chromatography and normal phase separations is reported. The geopolymers were synthesized by reaction of synthetic aluminosilicate with potassium silicate (fumed silica dissolved in KOH) in a water-in-oil emulsion.

Supercharging and multiple reaction monitoring of high-molecular-weight intact proteins using triple quadrupole mass spectrometry.

Rationale: Different supercharging agents were tested to study their effect on the intensity and charge state distributions of high-molecular-weight intact proteins. The goal of this work was to increase chargeability and ionization efficiency for proteins ranging from 66 to 150 kDa, to enable subsequent optimization of multiple reaction monitoring (MRM) mode transitions with a triple quadrupole mass spectrometer for potential top-down quantitative analysis.

Methods: Supercharging agents, such as meta-nitrobenzyl alcohol (m-NBA), dimethylsulfoxide, trifluoroethanol (TFE), and sulfolane were tested in different concentrations in 50/50 acetonitrile/water with 0.