In vitro protein–polysaccharide conjugation: Tyrosinase‐catalyzed conjugation of gelatin and chitosan

• DOI: 10.1002/bip.10196
• Publication Date: 2002-09-11T02:05:28Z
• Authors: Tianhong Chen; Heather D. Embree; Li‐Qun Wu; Gregory F. Payne
• Keywords: Gelatin; Chitosanase

Abstract The enzyme tyrosinase was used for the in vitro conjugation of protein gelatin to polysaccharide chitosan. Tyrosinases are oxidative enzymes that convert accessible tyrosine residues proteins into reactive o ‐quinone moieties. Spectrophotometric and dissolved oxygen studies indicate can oxidize we estimate 1 5 chains undergo reaction. Oxidized tyrosyl (i.e., quinone residues) nonenzymatic reactions with available nucleophiles such as nucleophilic amino groups Ultraviolet/visible, H‐NMR, ir provided chemical evidence oxidized Physical by dynamic viscometry, which indicated catalyzes sol‐to‐gel conversion gelatin/chitosan mixtures. gels formed from tyrosinase‐catalyzed were observed differ cooling gelatin. In contrast gels, tyrosinase‐generated had different thermal behavior broken chitosan‐hydrolyzing chitosanase. These results demonstrate be exploited formation protein–polysaccharide conjugates offer interesting mechanical properties. © 2002 Wiley Periodicals, Inc. Biopolymers 64: 292–302,