The lipopolysaccharide‐binding protein participating in hemocyte nodule formation in the silkworm Bombyx mori is a novel member of the C‐type lectin superfamily with two different tandem carbohydrate‐recognition domains¹

Abstract

We recently isolated and characterized the lipopolysaccharide (LPS)-binding protein, BmLBP, from the larval hemolymph of the silkworm Bombyx mori. BmLBP is a pattern recognition molecule that recognizes the lipid A portion of LPS and participates in a cellular defense reaction. This paper describes the cDNA cloning of BmLBP. The deduced amino acid sequence of BmLBP revealed that BmLBP is a novel member of the C-type lectin superfamily with a unique structural feature that consists of two different carbohydrate-recognition domains in tandem, a short and a long form.z 1999 Federation of European Biochemical Societies.

Immulectin-2, a Lipopolysaccharide-specific Lectin from an Insect, Manduca sexta, Is Induced in Response to Gram-negative Bacteria

“…It contains two C-type CRDs, an amino-terminal domain, CRD1 (residues 1-136), and a carboxyl-terminal domain, CRD2 (residues 137-288). This feature of IML-2 is similar to another M. sexta lectin, immulectin (now designated IML-1) (16), and to lectins from other two insect species: LPS-binding proteins from the silkworm, B. mori (15), and the fall webworm, H. cunea (18). Fig.…”

“…We have isolated from plasma of the tobacco hornworm, M. sexta, a C-type lectin, IML-2, that binds to Gram-negative bacteria and stimulates phenol oxidase activation. IML-2 contains two CRDs, an organization that is similar to that of immulectin-1, another C-type lectin from M. sexta (16), and C-type lectins from two other lepidopteran insect species, B. mori (15) and H. cunea (18). M. sexta IML-2 is 55% identical in sequence to B. mori lipopolysaccharide-binding protein, 47% identical to H. cunea lectin, and only 27% identical to M. sexta IML-1.…”

“…Among these insect lectins is a group of C-type lectins that contain two tandem CRDs. Lectins of this new type include immulectin-1 from the tobacco hornworm, Manduca sexta (16), and LPS-binding lectins from the silkworm, Bombyx mori (15) and the fall webworm, Hyphantria cunea (18,19). We report here an LPS-specific C-type lectin, immulectin-2 from M. sexta, which contains two CRDs and binds to Gram-negative bacteria and to LPS and stimulates phenol oxidase activation in hemolymph.…”

“…These C-type lectins function in insect innate immune system by participating in hemocyte nodule formation (14,15), activating prophenol oxidase in hemolymph (16), and opsonization (17). Among these insect lectins is a group of C-type lectins that contain two tandem CRDs.…”

Two carbohydrate recognition domains of Hyphantria cunea lectin bind to bacterial lipopolysaccharides through O‐specific chain

“…The deduced amino acid sequence of H. cunea lectin showed a signi¢cant similarity with the lipopolysaccharide (LPS) binding protein of the American cockroach, that is related in sequence to the C-type lectins of vertebrates [3,4]. Recently, the studies of BmLBP (LPS binding protein from Bombyx mori) and immunolectin revealed that they contain two di¡erent CRDs [5,6]. The amino acid sequence alignment of H. cunea lectin, BmLBP and immunolectin shows that C-type lectins with two CRDs are conserved in three lepidopterian insects, H. cunea, B. mori and Manduca sexta (Fig.…”