High-Yield Production in Escherichia coli of Fungal Immunomodulatory Protein Isolated from Flammulina velutipes and Its Bioactivity Assay in Vivo.
A fungal immunomodulatory protein isolated from Flammulina velutipes (FIP-fve) has structural similarity to the variable region of the immunoglobulin heavy chain. In the present study, the recombinant bioactive FIP-fve protein with a His-tag in  N-terminal of recombinant protein was expressed in transetta (DE3) at a high level under the optimized culturing conditions of 0.2 mM IPTG and 28 °C. The efficiency of the purification was improved with additional ultrasonication to the process of lysozyme lysis. The yield of the bioactive FIP-fve protein with 97.1% purity reached 29.1 mg/L with a large quantity for industrial applications. Enzyme-linked immunosorbent assay showed a maximum increase in interleukin-2 (IL-2) and gamma interferon (IFN-γ) for the mice serum group of 5 mg/kg body mass (p < 0.01) with three doses of His-FIP-fve. However, the production of IL-4 had no apparent difference compared to the control.
Key Laboratory of Saline-alkali Vegetation Ecology Restoration in Oil Field (SAVER), Ministry of Education, Alkali Soil Natural Environmental Science Center (ASNESC),  Northeast Forestry University, Harbin Hexing Road, Harbin 150040, China. shenkuiliu@nefu.edu.cn.
Xianghui
X
Kong
Jiechi
J
Zhang
Xue
X
Han
Piqi
P
Zhang
Xiaodong
X
Dai
Jianing
J
Liu
Xinxin
X
Zhang
Imshik
I
Lee
Shenkui
S
Liu