Molecular characteristics and physiological functions of major royal jelly protein 1 oligomer

Abstract

Royal jelly (RJ) contains numerous components, including proteins. Major royal jelly protein (MRJP) 1 is the most abundant protein among the soluble RJ proteins. In this study, we focused the molecular characteristics and functions of MRJP 1 oligomer. MRJP 1 oligomer purified using HPLC techniques was subjected to the following analyses. The molecular weight of MRJP 1 oligomer was found to be 290 kDa using Blue Native (BN)‐PAGE. MRJP 1 oligomer was separated into 55‐ and 5 kDa spots on 2‐dimensional BN/SDS‐PAGE. The 55 kDa protein was identified as MRJP 1 monomer by proteome analysis, while the 5 kDa protein was identified as Apisimin by N‐terminal amino acid sequencing, and this protein may function as a subunit‐joining protein within MRJP 1 oligomer. Furthermore, MRJP 1 oligomer dose‐dependently enhanced and sustained cell proliferation in the human lymphoid cell line Jurkat. In conclusion, MRJP 1 oligomer is a protein comprising MRJP 1 monomer and Apisimin, and has cell proliferation activity.