Freeze-Drying of Glycoprotein GFPS1b from Grifola frondosa GF9801: Drying Kinetics, Functional, Conformational, and Topographical Changes

Abstract

GFPS1b is an antitumor glycoprotein isolated and purified from the mycelia of Grifola frondosa GF9801. In the present study, freeze drying and hot air drying of GFPS1b were compared according to their drying kinetics, functional/conformational/topographical changes, and anti-proliferative activities for the first time. UV spectroscopy, FT-IR, SEM, and compositional analysis were conducted to evaluate the structural changes of GFPS1b after the above drying processes. Results showed that physicochemical and anti-proliferative properties of GFPS1b differed from each other after the two drying treatments. The freeze-dried GFPS1b-F showed the significant advantages over hot-air-dried GFPS1b-A due to its higher product yield, higher protein content, total sugar content, uronic acid content, higher solubility, and anti-proliferative activity. This study revealed that different drying methods used for preparation of glycoprotein GFPS1b could significantly affect the physicochemical properties and structure, which in turn adversely affect the biological activity of GFPS1b.

Keywords:

• Anti-proliferative activity
• Drying methods
• Grifola frondosa
• Physicochemical properties

ACKNOWLEDGMENTS

This work was supported by funding from National Natural Science Foundation of China (NSFC 31101269), National Science & Technology Pillar Program during the Twelfth Five-year Plan Period (2012BAD36B05), China Postdoctoral Science special Foundation (2013T60648), the China Postdoctoral Science Foundation (2012M511702), 2012 Excellent Key Young Teachers Project of Jiangsu University, Graduate Research and Innovation Projects of Jiangsu Province (CXLX12_0670); Advanced Programs of Jiangxi Postdoctoral Science Foundation ([2012]195); the Research Foundation for Advanced Talents of Jiangsu University; Science & Technology Platform Construction Program of Jiangxi Province.