RETENTIVE AND ENANTIOSELECTIVE PROPERTIES OF OVOMUCOID-BONDED SILICA COLUMNS - INFLUENCE OF PROTEIN PURITY AND ISOLATION METHOD

The influence of protein purity and isolation method on the chiral res olution of racemates on ovomucoid-bonded materials has been investigat ed. Chicken ovomucoid (OMCHI) and turkey ovomucoid (OMTKY) were obtain ed from commercial sources, and were isolated by precipitation with ac etone from their corresponding egg whites. Further, crude OMCHI protei n was fractionated by cation-exchange chromatography into two fraction s, pure OMCHI and an unknown protein fraction. The OMCHI, fractionated OMCHI and OMTKY proteins were characterized by N-terminal sequencing and trypsin-inhibitory activity. Their purity was checked by reversed- phase chromatography. The results reveal that the commercial OMCHI, an d the isolated OMCHI and OMTKY are crude preparations and that an unkn own protein fraction is present in each crude ovomucoid protein. The O MCHI, fractionated OMCHI and OMTKY proteins were bound to aminopropyl- silica gels activated by N,N'-disuccinimidyl carbonate to test the ret entive and enantioselective properties of those materials. The result suggests that the unknown protein fraction could be responsible for ch iral recognition ability of the OMCHI and OMTKY columns.