Abstract: To optimize the extraction condition for the antibacterial glycoproteins from the nidamental gland of the Sepiella maindroni and explore the antibacterial activity of the glycoproteins,this paper optimized the extraction process of glycoprotein by response surface test on the basis of single factor test.At the same time,the crude glycoprotein was separated and purified by DEAE-52 Cellulose ion exchange column chromatography and identified by electrophoresis.The results showed that the optimized parameters were 0.43 mol/L of NaOH,extraction times of 2.8 h,extraction temperature of 27 ℃,and liquid to material ratio was 30∶1.In this condition,the actual antibacterial crude glycoprotein yield was 8.31%±0.18%.Two glycoprotein components,component 2 and component 3,were efficiently separated by DEAE-52 Cellulose ion exchange column chromatography.The SDS-PAGE electrophoresis showed that the active protein components of the two glycoproteins were single proteins.The results also showed that component 2 and component 3 had very significant antibacterial effect against Escherichia coli and Staphylococcus aureus(P<0.01),and the antibacterial activity was much stronger than the same concentration of potassium sorbate (P<0.01).This study can provide a theoretical basis for the development and utilization of glycoproteins from nidamental gland of the Sepiella maindroni in biological preservatives.

Key words: Sepiella maindroni, nidamental gland, glycoproteins, antibacterial activity