Purification and functional characterization of lectin with phenoloxidase activity from the hemolymph of cockroach, Periplaneta americana

Abstract

Lectins also identified as hemagglutinins are multivalent proteins and on account of their fine sugar-binding specificity play an important role in immune system of invertebrates. The present study was carried out on the hemolymph lectin of cockroach, Periplaneta americana with appropriate screening and purification to understand its molecular as well as functional nature. The lectin from the hemolymph was purified using ion-exchange chromatography. The approximate molecular weight of purified lectin was 340 kDa as determined by FPLC analysis. Rabbit erythrocytes were highly agglutinated with purified lectin from the hemolymph of P. americana. The hemagglutination activity (HA) of lectin was specifically inhibited by fucose. Glycoproteins also inhibited the HA activity of lectin. The amino acid sequences of the purified lectin revealed homology with amino acid sequences of allergen proteins from P. americana. Purified lectin showed the highest phenoloxidase activity against dopamine. The activators such as exogenous proteases and LPS from Escherichia coli and Salmonella minnesota significantly enhanced the PO activity of the purified lectin. Besides, the presence of copper and hemocyanin conserved domain in the purified lectin provided a new facet that insects belonging to the ancient clade such as cockroaches retained some traces of evolutionary resemblance in possessing lectin of ancient origin.

A C‐type lectin with dual‐CRD from Tribolium castaneum is induced in response to bacterial challenge

“…In insects, CTLs are involved in enhancement of melanization, phagocytosis and encapsulation, [14][15][16][17] cell adhesion, 18 tissue regeneration, 19 regulating anti-fungal immunity, 20 bacterial clearance 21 and prophenoloxidase activation. 20,22 In some cases, CTLs show direct antibacterial activities or increase the production of antimicrobial peptides (AMPs). A short-form CTL from Amphioxus can directly kill microorganisms through binding microbial targets via interaction with peptidoglycan (PGN) and glucan.…”

Evidence for reduced immune gene diversity and activity during the evolution of termites

“…Evidence exists for the involvement of CTLs in haemocyte nodule formation, encapsulation, melanization and phagocytosis, with mechanisms that are mediated by recognition of pathogen surface molecules, such as lipopolysaccharide, mannose and lipid A, via CTL carbohydrate recognition domains [35,36]. A number of CTLs from cockroaches play a role in immunity, including facilitation of phagocytosis and activation of phenoloxidase activity [37][38][39][40]. LPSBPs are significantly expanded in cockroaches [41] and are thought to function as opsonins, by binding specific types of oligosaccharides in the lipopolysaccharide core of invading microorganisms [38,42,43].…”

Purification and Partial Characterization of Agglutinin Lectin from Heamolymph of German Cockroach, Blattella germanica

“…Insects lack specific acquired nonself recognition systems such as antibody in vertebrates, and lectins molecules have main role of nonself recognition in the innate immune response (1)(2)(3)(4). Lectins can agglutinate foreign matter and thus become to be it more suitable for understanding.…”