Inhibition of specific degradation of 57-kDa protein in royal jelly during storage by ethylenediaminetetraacetic acid.

Abstract

We have previously shown that 57-kDa protein in royal jelly (RJ) was specifically degraded in proportion to both storage temperature and storage period, and we suggested that it could be useful as a marker of freshness of RJ (Kamakura, M., Fukuda, T., Fukushima, M. and Yonekura, M., Biosci. Biotechnol. Biochem., 65, 277-284 (2001).). Here, we investigated the effects of various proteinase inhibitors on proteinase activity in RJ and on the specific degradation of 57-kDa protein during storage. Ethylenediaminetetraacetic acid (EDTA), but not other inhibitors, inhibited the proteinase activity in RJ, and dose-dependently suppressed storage-dependent degradation of 57-kDa protein. These results suggest that EDTA inhibits a specific proteinase activity in RJ, thereby suppressing the degradation of 57-kDa protein during storage at high temperature.