Purification, characterization and functional role of lectin from green tiger shrimp Penaeus semisulcatus

The present study reports the purification and characterization of immune molecule lectin from the green tiger shrimp Penaeus semiculcatus, which involves the non-self-recognition mechanism to destroy the infectious pathogens that continuously threaten their survival. P. semisulcatus lectin (Ps-Lec) was purified by affinity chromatography with mannose coupled sepharose CL-4B column and showed the 37 and 118 kDa subunits in SDS-PAGE. The surface morphology of purified Ps-Lec exhibits the crystalline and aggregated nature in Transmission electron microscopy (TEM) analysis. Functional analysis of purified Ps-Lec showed that the broad spectrum of bacterial agglutination activity against Gram-positive and Gram-negative bacteria. In addition, Ps-Lec had the ability to involve in the haemoagglutination activity, which agglutinates the several vertebrate erythrocytes tested, and the haemagglutination titres were observed under light microscopy. Interestingly, Ps-Lec also exhibits the fungal aggregation activity against Candida albicans, this is the first report regarding the β-glucan recognition ability of fungal aggregation of Ps-Lec. Moreover, phenoloxidase activity was triggered by the Ps-Lec when compared to control. The present study reveals that Ps-Lec is an important multifunctional humoral defence protein plays a significant role against the bacterial and fungal cells.