In vitro and in silico studies on cell adhesion protein peroxinectin from Fenneropenaeus indicus and screening of heme blockers against activity.

In invertebrates, the prophenoloxidase (proPO) pathway is involved in the phenol-like antioxidant production against invading pathogens. Overproduction of melanin and phenolic substances leads to the disruption of hemocytes (own host cells); therefore, there is a prerequisite to regulate the antioxidant production, which is performed by the proteases and proPO-associated cell adhesion protein peroxinectin (PX). PX is a macromolecular structure consisting of protein involved in the proPO pathway, which is a potential target in the regulatory mechanism in crustaceans. In the proPO cascade, pattern recognition proteins initiate the proPO cascade by the consequent reaction, and PX is involved in the key step in the regulatory mechanism of phenoloxidase enzyme synthesis. In the present study, Indian white shrimp Fenneropenaeus indicus PX (Fein-PX) gene sequence was used. Upregulation of Fein-PX was determined using immunostimulants β-glucan (agonists) and examined its expression by quantitative RT-PCR. To find the downregulation or negative regulation of Fein-PX, inhibitors were screened, and its 3D model provides molecular insights into the rationale inhibitor design for developing an effective molecule against Fein-PX.