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

Identification of the chitin-binding proteins from the larval proteins of silkworm, Bombyx mori

“…Silkworms also produce multiple low molecular mass 30 kDa lipoproteins. A recent study of two low molecular mass 30 kDa lipoproteins, 6G1 and 19G1, revealed that they specifically bound to b-glucan, not to chitin (Ujita et al, 2005). There were no data to show what happened to another main 30 kDa lipoprotein, 21 G1.…”

Crystal structure of the 30 K protein from the silkworm Bombyx mori reveals a new member of the β-trefoil superfamily

“…A recombinant B. mori 30 K protein 6G1 (Bmlp1) was reported to bind glucans and participate in the activation of prophenoloxidase cascade. Also, Bmlp1 could interfere with hyphal growth of the entomopathogenic fungus Paecilomyces tenuipes (Ujita et al, 2005). Recently, several anti-apoptotic fractions from B. mori hemolymph were obtained.…”

“…However, the lipid content of these proteins and their functional relationships to human lipoproteins were unknown (Chapman, 1980). 30 K proteins had also been shown to bind to glucose, maltose and glucans, suggesting their involvement in insect self-defense systems (Ujita et al, 2005). In addition, 30 K proteins had been found to exhibit anti-apoptotic activity (Kim et al, 2001) and to be involved in translocating chymotrypsin inhibitor-8 to the membrane of the midgut (Ueno et al, 2006).…”

Activation of the Silkworm Cytokine by Bacterial and Fungal Cell Wall Components via a Reactive Oxygen Species-triggered Mechanism

“…For example, PGRP is well characterized, and it mediates the melanization and production of antimicrobial peptides (39,44). ␤GRP, Gram-negative bacteriabinding protein, and apolipoprotein bind to glucan (40,(45)(46)(47). These receptors are candidates that might be involved in the first step of PP activation.…”