Abstract
A novel protein-polysaccharide conjugate NFP-A4 was isolated and purified from water extracts of Nervilia fordii. The polysaccharide chain of NFP-A4 was found to contain D-galacturonic acid, D-galactose, D-glucose, L-arabinose, D-glucuronic acid, L-rhamnose, and D-mannose. The protein content of NFP-A4 was determined to be 12.83%, and it was bound to the polysaccharide chain via O-linkages at the serine and threonine residues. NFP-A4 was found to significantly activate macrophages and also induce immunomodulatory responses. These data suggest that NFP-A4 is a major bioactive component of N. fordii and may be responsible for many of its therapeutic properties.
Disclosure statement
The authors declare no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.