Specific Binding of SilkwormBombyx mori30-kDa Lipoproteins to Carbohydrates Containing Glucose

Glucan-Binding Activity of Silkworm 30-kDa Apolipoprotein and Its Involvement in Defense against Fungal Infection

“…The binding specificity of 6G1 apolipoprotein was identified by affinity chromatography on various insoluble polysaccharides. 9,11) The purified GST-6G1 fusion protein was dissolved in a loading buffer containing 125 mM NaCl, 10 mM CaCl 2 , and 25 mM Tris-HCl, pH 7.5. The fusion protein solution (0.5 ml) was put on a 1-ml column of -glucan (from Saccharomyces cerevisiae, Sigma), chitin beads (New England Biolabs), mannan (Sigma), or peptidoglycan (from Staphylococcus aureus, Wako) equilibrated with the loading buffer, and then washed with 10 ml of the loading buffer.…”

“…4,5) Recently we found that B. mori 30-kDa lipoproteins (6G1 and 19G1), major plasma proteins of the fifth instar larvae and of pupae, [6][7][8] bind to -glucan, a fungal immune elicitor. 9) These lipoproteins are synthesized in fat body of both sexes and are secreted into the hemolymph. Biosynthesis of the 30-kDa lipoproteins was shown to be developmentally regulated in a stagedependent manner at the transcriptional level in fat body, although their biological functions remain unclear.…”

The Mulberry Silkworm—A New Source of Bioactive Proteins

“…The 30-kDa LPs are used as the source of nutrition after enzymatic digestion [33]. Moreover, 30-kDa LPs are probably also involved in immune response pathway, namely antifungal defence system, because they are able to specifically bind glucose and glucans, which are the main components of fungal cell walls [39,40]. What is more, it was reported that a member of the 30-kDa LPs family activates a prophenoloxidase cascade, the immune response pathway [40].…”

Carbohydrate Binding Specificity of the Recombinant Chitin-binding Domain of Human Macrophage Chitinase

“…The binding speciˆcity of HCBD was identiˆed by a‹nity chromatography on various insoluble polysaccharides. 9,12) The puriˆed GST-HCBD fusion protein was dissolved in a loading buŠer containing 125 mM NaCl, 10 mM CaCl2, and 25 mM Tris-HCl, pH 7.5. The fusion protein solution (0.5 ml) was put on a 1-ml column of chitin beads (New England Biolabs), glucan, xylan, or mannan (all from Sigma) equilibrated with the loading buŠer, and then washed with 5 ml of the loading buŠer.…”