Purification, Characterization and
Immunological Function
of a New Polysaccharide-protein Complex (LE) from
Cultured Mycelia of Lentinus edodes
LIU Mei-Qin*, LI Jian-Zhong and KONG Fan-Zuo
( Research Center for Eco-environmental Sciences, the Chinese Academy of
Sciences, Beijing 100085, China )
Abstract¡¡¡¡LE was obtained through
extraction of cultured mycelia of Lentinus edodes by hot water,
ethanol, and Sevag method, followed by the purification by DEAE-cellulose
column chromatography. LE was proved to be homogeneous by DEAE-cellulose column
chromatography, UV spectroscopy and polyacrylamide gel electrophoresis. As
identified by IR and UV, it was a polysaccharide-protein complex, with the molecular
weight of about 5.08¡Á105 by light diffusion method, and contained
94.2% carbohydrate and 5.8% protein. Complete acid hydrolysis revealed that its
carbohydrate moiety was composed of glucose only and its protein portion
consisted mainly of Asx, Glx, Ala and other amino acids. The structure of
carbohydrate moiety was determined by methylation, hydrolysis, acetylation,
TLC, £Û1H£ÝNMR etc. and was shown that it
consisted of 2,4-di-O-Me-Glu, 2,4,6-tri-O-Me-Glu, 2,3,4,6-tetra-O-Me-Glu, at a
ratio of about 1¡Ã2¡Ã1. The results suggested that LE had a ¦Â-(1¡ú3)-D-glucan
backbone with ¦Â-(1¡ú6)-D-glucose side chains. Furthermore, RT-PCR was used to
analyze cytokine gene expression and bioassay was used to analyze cytokine
production in the human peripheral blood mononuclear cells untreated and
treated with LE. By treatment of LE, the expression level of IL-2 and TNF-¦Á
genes were increased in the treated human peripheral blood mononuclear cells.
These results suggest that LE may induce some immune responses.
Key Words¡¡¡¡Lentinus edodes; polysaccharide-protein
complex LE; cytokines
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