Abstract: A protein from spinach (Spinacia deracea Mill. ) leaves was isolated and purified by fractional precipitation and hydroxyapatite column chromatography, and in combination with electrophoresis and electroelution. The protein had a light red-brown color and an absorption peak at 455 nm. SDS-PAGE analysis showed that the protein subunit molecular weight was 45 kD. These characterizations indicates that the isolated protein was choline monooxygenase (CMO), and antisem of the CMO protein from rabbit was obtained. The antisera could cross-react with antibodies of choline oxidase that was isolated from bacteria (Alcaligenes species), but could not be recognized by antibodies of betaine aldehyde dehydrogenase from higher plants.

Key words: Choline monooxygenase, Spinach, Antibody preparation