Separation of chitooligosaccharides and the potent effects on gene expression of cell surface receptor CR3

Chitooligosaccharides were prepared through hydrolysis of colloidal chitosan by enzyme source from Aspergillus fumigatus BSF114. Chitosan pentamer (COS5) and chitosan hexamer (COS6) were isolated and purified from COS by the ultra-filtration, nano-filtration, ethanol precipitation and the CM-Sephadex C-25 column. COS5 consisted of (GlcN)₄ (59.84%) and (GLcN)₅ (40.16%). COS6, however, mainly consisted of (GLcN)₆ (93.11%) and (GLcN)₅ (6.89%). Effects of COS5 and COS6 in vivo and in vitro on gene expression of cell surface CR3 receptor were investigated by relatively quantitative RT-PCR and ELISA. The results showed that the expression of CR3 mRNA could be promoted by both COS5 and COS6. The promotion effect caused by COS6 was greater than that of COS5.