ENANTIOSELECTIVITY OF BOVINE SERUM ALBUMIN-BONDED COLUMNS PRODUCED WITH ISOLATED PROTEIN-FRAGMENTS

The enantioselectivity of bovine serum albumin (BSA)-bonded columns produced with isolated protein fragments was investigated. The BSA fragment BSA-FG75 was isolated by size-exclusion chromatography followed by peptic digestion of BSA. The isolated BSA-FG75 was a mixture of three peptides, and was mainly an N-terminal half peptide(s) with an average molecular mass of about 35 000. The BSA and BSA-FG75 proteins were bound to aminopropylsilica gels activated by N,N'-disuccinimidyl carbonate. The amounts of the proteins bound were about 2 and 5.5 mu mol/g for the BSA and BSA-FG75, respectively. Chiral recognition of 2-arylpropionic acid derivatives, benzodiazepines, warfarin and benzoin was obtained with the BSA-FG75-bonded columns, but no chiral recognition of tryptophan or kynurenine was obtained. The intact BSA column gave a higher enantioselectivity than the BSA-FG75 column for most of the compounds tested, whereas the BSA-FG75 column gave a higher enantioselectivity than the intact BSA column for lorazepam and benzoin, and had a higher capacity for benzoin. These results are due to a higher density of chiral recognition site(s) on the BSA-FG75 column. Also, the BSA-FG75 column was as stable as the intact BSA column for a continuous flow of eluent.