THE ABSENCE OF CHIRAL RECOGNITION ABILITY IN OVOMUCOID - OVOGLYCOPROTEIN-BONDED HPLC STATIONARY PHASES FOR CHIRAL RECOGNITION

Commercial chicken ovomucoid (OMCHI) and OMCHI, isolated by precipitation of egg whites with organic solvents, both of which as crude products, were fractionated by anion- and cation exchange chromatography. The obtained four fractions were characterized by reversed-phase chromatography, N-terminal sequencing, matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry, determination of sugar contents, and trypsin-inhibitory activities. Three fractions were OMCHI variants differing in carbohydrate composition, especially in sialic acid content, and the other fraction was tentatively termed ovoglycoprotein (OGCHI). The OMCHI and OGCHI are different in physicochemical and biochemical properties: average moleculare weight, 26 000-27 700 for OMCHI variants and 29 700 for OGCHI; N-terminal amino acid, Ala for OMCHI and Thr for OGCHI; and trypsin-inhibitory activity, positive for OMCHI and negative for OGCHI. These OMCHI variants and OGCHI were bound to aminopropyl silica gels to evaluate chiral recognition ability. OMCHI is reported to have chiral recognition ability (Miwa, T.; et al. Chem. Pharm. Bull. 1987, 35, 682-686). However, neither OMCHI variant had appreciable chiral recognition ability, while the OGCHI had excellent chiral recognition properties as compared to those of the OMCHI reported previously. This reveals that the chiral recognition ability of the OMCHI reported previously comes from the OGCHI, which is present in crude OMCHI as an impurity.