title: Purification, characterization and functional analysis of a novel β-1, 3-glucan binding protein from green tiger shrimp Penaeus semisulcatus.
abstract: A β-1, 3-Glucan binding protein (β-GBP) was isolated from green tiger shrimp Penaeus semisulcatus and purified using laminarin precipitation and affinity chromatography on laminarin-Sepharose 6B column respectively. P. semisulcatus β-GBP exhibits a single band with a molecular weight of 112 kDa on SDS-PAGE and pI of 5.9 in isoelectric focusing (IEF). Negative staining of P. semisulcatus β-GBP showed large aggregates with crystalline surface when viewed by Electron Microscopy. Circular dichroism spectra of P. semisulcatus β-GBP showed broad negative minimum wavelength extending from 200 to 250 nm can be attributed to the presence of β-sheets in its secondary structure. P. semisulcatus β-GBP comprises the specific binding affinity with the polysaccharide β-1, 3-glucans (laminarin), this recognition and binding leads to the activation of prophenoloxidase cascade. Interestingly, P. semisulcatus β-GBP also involved in the agglutination of baker's yeast, bacteria, erythrocytes (RBCs) and enhances the PO activity. Herein, we have investigated the importance of β-GBP in innate immune response of P. semisulcatus and they implicate the evolutionary link with similar proteins found in other invertebrates.
authors.affiliation: Crustacean Molecular Biology and Genomics Lab, Department of Animal Health and Management, Alagappa University, Karaikudi 630 003, Tamil Nadu, India.
authors.forename: Jeyachandran
authors.initials: J
authors.lastname: Sivakamavalli
authors.forename: Baskaralingam
authors.initials: B
authors.lastname: Vaseeharan
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D004156:Catechol Oxidase / Q000235:genetics / Q000378:metabolism; D004792:Enzyme Precursors / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology; D037102:Lectins / Q000235:genetics / Q000378:metabolism*; D033561:Penaeidae / Q000235:genetics / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D004792:Enzyme Precursors; D037102:Lectins; C037937:glucan-binding proteins; C038451:pro-phenoloxidase; D004156:Catechol Oxidase
keywords: Innate immunity; Shrimp; proPhenoloxidase (proPO) activity; β-1, 3-glucan binding protein (β-GBP)