ABSTRACT
@#Adjuvant is the key factor for many new vaccines to play a protective role. The addition of adjuvant can not only reduce the amount of antigen,but also increase the immunogenicity of its antigen,and stimulate the strong immune response of body. Chitosan,as the product of natural polysaccharide chitin removing part of acetyl group,has the characteristics of adhesion,permeability,biocompatibility and so on,and has been widely studied and applied as a vaccine adjuvant. As a novel adjuvant,it can not only help to induce cellular and humoral immunity,but also activate mucosal immunity. This review discussed the recent progress of chitosan and quaternized chitosan as vaccine adjuvants and the related mechanism.
ABSTRACT
OBJECTIVE: To chemically modify superoxide dismutase (SOD) with 6-O-quaternized chitosan. METHODS: 2, 3- Epoxypropyl trimethyl ammonium chloride was grafted to reactive C6-OH of chitosan to obtain O-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (O-HTCC). O-HTCC was covalently coupled to SOD via EDC/NHS-mediated reaction, followed by purification on DEAE Sepharose fast flow column. The conjugates were analyzed by SDS-PAGE, HPLC, and circular dichroism. The enzyme activity of the conjugates was determined using pyrogallol autoxidation assay. RESULTS: SOD was successfully modified by O-HTCC at an efficiency of 90%. The homogeneous conjugates showed similar secondary structure and retained 81.1% of enzyme activity compared with native SOD. CONCLUSION: SOD can be efficiently modified by O-HTCC to prepare O-HTCC-SOD conjugates with high activity retention rate.