A New Fungal Immunomodulatory Protein, FIP‐fve Isolated from the Edible Mushroom, Flammulina velutipes and its Complete Amino Acid Sequence

A new fungal immunomodulatory protein (FIP‐fve) has been isolated and purified from the edible golden needle mushroom (Flammulina velutipes). The apparent molecular mass of FIP‐fve determined by SDS/PAGE agrees well with the value of 12 704 Da calculated from its amino acid composition and sequence. The complete amino acid sequence of FIP‐fve was elucidated by protein sequencing techniques. FIP‐fve consists of 114 amino acid residues with an acetylated amino end, and lacks methionine, half‐cystine and histidine residues. FIP‐fve was able to hemagglutinate human red blood cells. The immunomodulatory activity of FIP‐fve was demonstrated by its stimulatory activity toward human peripheral blood lymphocytes, and its suppression of systemic anaphylaxis reactions and local swelling of mouse footpads. FIP‐fve was found to enhance the transcriptional expression of interleukin‐2 and interferon‐γ.