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

Commercial chicken ovomucoid (OMCHI) and OMCHI, isolated by precipitat ion of egg whites with organic solvents, both of which as crude produc ts, were fractionated by anion- and cation exchange chromatography. Th e obtained four fractions were characterized by reversed-phase chromat ography, N-terminal sequencing, matrix-assisted laser desorption ioniz ation time-of-flight (MALDI-TOF) mass spectrometry, determination of s ugar contents, and trypsin-inhibitory activities. Three fractions were OMCHI variants differing in carbohydrate composition, especially in s ialic acid content, and the other fraction was tentatively termed ovog lycoprotein (OGCHI). The OMCHI and OGCHI are different in physicochemi cal and biochemical properties: average moleculare weight, 26 000-27 7 00 for OMCHI variants and 29 700 for OGCHI; N-terminal amino acid, Ala for OMCHI and Thr for OGCHI; and trypsin-inhibitory activity, positiv e for OMCHI and negative for OGCHI. These OMCHI variants and OGCHI wer e bound to aminopropyl silica gels to evaluate chiral recognition abil ity. OMCHI is reported to have chiral recognition ability (Miwa, T.; e t al. Chem. Pharm. Bull. 1987, 35, 682-686). However, neither OMCHI va riant had appreciable chiral recognition ability, while the OGCHI had excellent chiral recognition properties as compared to those of the OM CHI reported previously. This reveals that the chiral recognition abil ity of the OMCHI reported previously comes from the OGCHI, which is pr esent in crude OMCHI as an impurity.