Hydrophobic interaction chromatography of incompletely methylated transfer RNA from Escherichia coli on octyl-sepharose

Polymer-based monolithic microcolumns for hydrophobic interaction chromatography of proteins

Monolithic capillary columns for hydrophobic interaction chromatography (HIC) have been prepared by thermally initiated, single-step in situ polymerization of mixtures of monovinyl monomers including butyl methacrylate and/or 2-hydroxyethyl methacrylate, with a divinyl crosslinker glycerol dimethacrylate or 1,4-butanediol dimethacrylate using two different porogen systems. Two porogenic solvent mixtures were used; one "hydrophilic", consisting of water, butanediol, and propanol, and one "hydrophobic," comprising dodecanol and cyclohexanol. The porous structures of the monoliths were characterized and their performance was demonstrated with a separation of a mixture of myoglobin, ribonuclease A, and lysozyme under conditions typical of HIC.

Specific purification of glyceraldehyde-3-phosphate dehydrogenase by hydrophobic chromatography on immobilized colchicine

Hydrophobic column chromatography of bovine brain extracts (40-80% ammonium sulfate fraction) on immobilized colchicine resulted in the selective elution of one major protein with decreasing ionic strength of medium. This protein was identified as glyceraldehyde-3-phosphate dehydrogenase (GAPDH; EC 1.2.1.1) on the basis of its biochemical properties, N-terminal amino-acid sequence and enzymatic activity. The present method enabled GAPDH to be isolated with a high recovery (80%; 184 mg/kg brain) and could be of potential use for the purification of GAPDH from various tissues.

Hydrophobic interaction chromatography

Hydrophobic interaction chromatography (HIC) is emerging as a useful technique for the separation of biological compounds. Advances in the past two years in HIC applications, stationary phases, eluents, and theory are reviewed. Recent applications of HIC processes include analytical and semi-preparative separations of a variety of proteins, such as isolectins, hemoglobins, calmodulin, and cardiotoxins. Additionally, HIC is being employed as a tool to investigate protein properties and mechanisms. Advances in HIC stationary phases include development of non-porous, microparticulate supports as well as supports with pore sizes up to 1000 Angstroms. Studies of HIC eluents have further shown the effects of mobile phase pH, water-structuring characterization, and surface tension increments on retention. Various retention mechanisms which have been presented are reviewed; and a correlation relating resolution to column and solute parameters is presented. Protein conformational effects at specific sites have been shown to have a significant impact on retention and specific examples illustrating such effects are discussed.

Resolution of RNA using high-performance liquid chromatography

High-performance liquid chromatographic techniques can be very effective for the resolution and isolation of nucleic acids. The characteristic ionic (phosphodiesters) and hydrophobic (nucleobases) properties of RNAs can be exploited for their separation. In this respect anion-exchange and reversed-phase chromatography have been successfully employed in the analysis and/or isolation of RNAs. In some cases, particularly tRNAs, chromatographic separations which rely upon multiple interactions between the solute and mobile and/or stationary phases have been highly effective. Mixed-mode chromatography involving simultaneous ionic and hydrophobic interactions, has been employed to resolve complex mixtures of tRNAs. Hydrophobic-interaction chromatography using gradients of decreasing salt concentration and weakly hydrophobic stationary phases has allowed the resolution of some tRNA mixtures as well as the analysis of modified materials.