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

Abstract

Royal jelly contains numerous components, including proteins. Major royal jelly protein (MRJP) 1 is the most abundant protein among the soluble royal jelly proteins. In its physiological state, MRJP 1 exists as a monomer and/or oligomer. This study focuses 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-PAGE. MRJP 1 oligomer was separated into 55 and 5 kDa spots on 2-D blue native/SDS-PAGE. The 55 kDa protein was identified as MRJP 1 monomer by proteome analysis, whereas 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. We also found that the oligomeric form included noncovalent bonds and was stable under heat treatment at 56 degrees C. 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 heat-resistant protein comprising MRJP 1 monomer and Apisimin, and has cell proliferation activity. These findings will contribute to further studies analyzing the effects of MRJP 1 in humans.

Calcium effect and pH-dependence on self-association and structural stability of the Apis mellifera major royal jelly protein 1

“…A tryptic peptide from apisin showed an identical sequence to the region Gln167-Lys182 of MRJP1 (Kimura et al 2003). Recently, it was revealed that MRJP1 forms an heterooligomeric complex with apisimin, which was suggested to serve as a subunit-joining protein within the MRJP1 oligomer (Tamura et al 2009a).…”

“…Three MRJP1 hypothetical glycosylation sites have been proposed based on its primary structure (Ohashi et al 1997). Another interesting feature of MRJPl is that it is present in monomeric and oligomeric forms in royal jelly (Simuth 2001;Tamura et al 2009a).…”

Polyphenol-Protein Complexes and Their Consequences for the Redox Activity, Structure and Function of Honey. A Current View and New Hypothesis – a Review

“…However, the degradation products of MRJP1 were also shown to have immune-stimulatory activities [ The expanding number of functions of the MRJP1 includes its signifi cant infl uence on honey structure. The MRJP1 has propensity for oligomerization, and in honey, it often forms a large, 350 kDa hetero-hexamer, known as apisin [Kimura et al, 1995[Kimura et al, , 1996] with a peptide named apisimin [Bilikova et al, 2002] that serves as a linker between the MRJP1 oligomers [Tamura et al, 2009]. The MRJP1 molecule is highly glycosylated [Kimura et al, 1995[Kimura et al, , 1996.…”

Quantification of Major Royal Jelly Protein 1 in Fresh Royal Jelly by Indirect Enzyme-Linked Immunosorbent Assay

“…MRJP1 is a 55-57 kDa protein as determined by SDS PAGE, and it is present in monomeric and multimeric forms in RJ. 6,7) Apisin is considered to be a multimer that consists of six molecules of monomeric form. 8) It has been reported that a 57-kDa protein derived from MRJP1 decreased in proportion with storage temperature and incubation time.…”