C-Terminal Fragment of Vitellogenin II, a Potential Yolkin Polypeptide Complex Precursor Protein-Heterologous Expression, Purification, and Immunoregulatory Activity

The aim of this research was to analyze the heterologous expression, purification, and immunoregulatory activity of recombinant YGP40 (rYGP40), the potential precursor of the yolkin peptide complex. The ygp40 coding sequence was codon optimized, successfully expressed in the E. coli system, and purified from inclusion bodies with a yield of about 1.1 mg/L of culture. This study showed that the protein exhibits immunomodulatory activity, expressed by the stimulation of TNF-alpha and IL-10 production and nitric oxide induction at a level comparable to that of the natural yolkin peptide complex obtained by other authors from hen egg yolk. At the highest dose of 100 mu g/mL, rYGP40 also caused the up-regulation of iNOS expression in murine bone marrow-derived macrophages (BMDM). Moreover, no cytotoxic effects of rYGP40 on the BMDM cell line were observed.

Automated summary

This research successfully expressed and purified recombinant YGP40, showing its immunomodulatory activity by stimulating cytokine production. Moreover, rYGP40 also up-regulated iNOS expression in murine macrophages without causing cytotoxic effects on the cell line.