Influence of eluent anions in boronate affinity chromatography

The influence of various anions on the retention of nucleosides and nucleotides to a boronate affinity chromatography column was examined. At pH 7.0, F− ions were found to produce the strongest affinity and the best separation of nucleosides from their 2′-deoxy analogues. 11B NMR studies indicated this was due in part to the propensity of F− to form tetrahedral fluoroboronate complexes. Using an eluent of 50 mM 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid and 500 mM KF at pH 7.0, the nucleotides nicotinamide—adenine dinucleotide and flavin—adenine dinucleotide were found to be strongly retained on a boronate column. These nucleotide-saturated columns were examined for their ability to retain the nucleotide-binding enzymes, glucose-6-phosphate dehydrogenase, lactate dehydrogenase and galactose oxidase. No retention of the enzymes was observed.