Proteins from Punctularia atropurpurascens with Biotechnological Applications

Abstract

Basidiomycetes are able to biodegrade waste and xenobiotic molecules through the production of extracellular enzymes. For example, white-rot fungi produce lignin-degrading enzymes which are capable of efficiently decolorizing dye solutions. Many mushrooms also produce lectins, a group of proteins which bind specifically to the carbohydrates in glycoconjugates. Several fungal lectins target their specificities towards oligosaccharides present in mammalian glycoproteins, thus constituting excellent ligands for the preparation of affinity adsorbents useful in isolation and characterization of these glycoproteins. In this study we isolated and characterized two different proteins, a lectin and a laccase, present in extracts from Punctularia atropurpurascens. The lectin isolated from the mycelium extract, was immobilized on activated-Sepharose and used to evaluate the interaction with three glycoproteins. The adsorbent was able to efficiently adsorb and elute bovine lactoferrin, constituting a promising tool for the purification of this glycoprotein. In vitro experiments revealed that the lectin also exhibited antimicrobial activity against Aspergillus niger. Laccase activity was detected in the extracellular extract from P. atropurpurascens. This enzyme, in both soluble and immobilized forms, was able to degrade Remazol Brilliant Blue R and Acid Blue 25 dyes. The biological activities found in this fungus demonstrate its potential for various biotechnological applications.