Isolation and characterization of proteases that hydrolyze royal jelly proteins from queen bee larvae of the honeybee, Apis mellifera

Royal jelly is a nutritious substance secreted from the hypopharyngeal and mandibular glands of worker bees that serves as the only food on which honeybee queen larvae and adults are fed and which causes them to develop into queen bees. Royal jelly is a protein-rich food and one of the most crucial factors for the growth of queen bees. In this study, we characterized the hydrolytic activity of enzymes from the homogenates of honeybee queen larvae on royal jelly proteins. Homogenates of 3-day-old queen bee larvae were capable of hydrolyzing royal jelly proteins under alkaline conditions. Following separation by cation exchange and gel filtration column chromatographies, two proteases of 38 and 28 kDa were found by SDS-PAGE. The protease of 38 kDa had a carboxypeptidase A-like activity and that of 28 kDa a chymotrypsin-like activity. These enzymes may turn out to be useful in the manufacturing of processed royal jelly.