Purification and characteristics of individual major royal jelly protein 1–3

Abstract

Major royal jelly proteins (MRJPs) are deemed to the most characteristic and abundant constituents in royal jelly. The present paper establishes a sequential process to purify the natural MRJP 1–3 by three different chromatographic procedures. Five individual proteins were obtained, including MRJP 1 oligomer 1, MRJP 1 oligomer 2, MRJP 1 monomer, MRJP 2 and MRJP 3s (contain three MRJP 3 variants) with a purity of 89.88%, 67.79%, 99.92%, 99.41%, and 99.97%, respectively. This is the first report that MRJP 1 mainly possesses three oligomers: a 228 kDa MRJP 1 oligomer 1, a 408 kDa MRJP 1 oligomer 2 and a 639 kDa MRJP 1 oligomer 3. We infer that MRJP 1 oligomer 3 (639 kDa) may be assembled by MRJP 1 oligomer 1 (228 kDa) and MRJP 1 oligomer 2 (408 kDa). The secondary structure of the purified MRJP 1–3 consisted predominantly of β-sheets and random coil in the native conformation. Our results will contribute to the physiological and physicochemical function of the purified individual MRJPs.

Keywords:

• MRJPs
• purity
• yield
• MRJP1 oligomers
• secondary structure

Acknowledgments

We thank the Protein Chemistry Facility at the Center for Biomedical Analysis of Tsinghua University for LC-MS/MS analysis.

Disclosure statement

The authors declare that there is no conflict of interest.

Supplementary material

Supplementary Figures 1 and 2 are available via the ‘Supplementary’ tab on the article’s online page (http://dx.doi.org/10.1080/00218839.2020.1761071).

Additional information

Funding

This research was supported by the Modern Agro-industry Technology Research System (CARS-44-KXJ19) and the Agricultural Science and Technology Innovation Program (CAAS-ASTIP-2015-IAR) from the Ministry of Agriculture of P.R. China.