TY - JOUR
T1 - Glucan-binding activity of silkworm 30-kDa apolipoprotein and its involvement in defense against fungal infection
AU - Ujita, Minoru
AU - Katsuno, Yosuke
AU - Kawachi, Ichiro
AU - Ueno, Yoshinori
AU - Banno, Yutaka
AU - Fujii, Hiroshi
AU - Hara, Akira
N1 - Funding Information:
We thank Dr. Eiji Yokoyama of Meijo University for useful discussion. This work was supported in part by Grants-in-Aid from the Ministry of Education, Culture, Sports, Science and Technology of Japan, and the Agricultural High-Tech Research Center of Meijo University, under the project Environmental Control through the Functions of Microorganisms.
PY - 2005/6
Y1 - 2005/6
N2 - The silkworm Bombyx mori 30-kDa lipoproteins (6G1 and 19G1), major components of the hemolymph, were shown to bind to glucans. 6G1 apolipoprotein was expressed as a fusion protein with glutathione S-transferase in Escherichia coli and assayed for its binding activity. The purified recombinant 6G1 apolipoprotein specifically bound to β-glucan, but not to chitin, mannan, peptidoglycan, or oligosaccharide chains on glycoproteins. The β-glucan binding of the recombinant 6G1 was inhibited by laminaribiose and laminarin, a soluble glucan, but not by lipopolysaccharide or insect blood sugar, trehalose at physiological concentration. Furthermore, the recombinant 6G1 was shown to participate in the activation of prophenoloxidase cascade and to interfere with hyphal growth of the entomopathogenic fungus Paecilomyces tenuipes, injected into pupae of B. mori. These results suggest that 6G1 lipoprotein plays a role in the protection of B. mori against invading fungi.
AB - The silkworm Bombyx mori 30-kDa lipoproteins (6G1 and 19G1), major components of the hemolymph, were shown to bind to glucans. 6G1 apolipoprotein was expressed as a fusion protein with glutathione S-transferase in Escherichia coli and assayed for its binding activity. The purified recombinant 6G1 apolipoprotein specifically bound to β-glucan, but not to chitin, mannan, peptidoglycan, or oligosaccharide chains on glycoproteins. The β-glucan binding of the recombinant 6G1 was inhibited by laminaribiose and laminarin, a soluble glucan, but not by lipopolysaccharide or insect blood sugar, trehalose at physiological concentration. Furthermore, the recombinant 6G1 was shown to participate in the activation of prophenoloxidase cascade and to interfere with hyphal growth of the entomopathogenic fungus Paecilomyces tenuipes, injected into pupae of B. mori. These results suggest that 6G1 lipoprotein plays a role in the protection of B. mori against invading fungi.
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U2 - 10.1271/bbb.69.1178
DO - 10.1271/bbb.69.1178
M3 - Article
C2 - 15973050
AN - SCOPUS:22444433560
SN - 0916-8451
VL - 69
SP - 1178
EP - 1185
JO - Bioscience, Biotechnology and Biochemistry
JF - Bioscience, Biotechnology and Biochemistry
IS - 6
ER -