title: Bifunctional role of a pattern recognition molecule β-1,3 glucan binding protein purified from mangrove crab Episesarma tetragonum.
abstract: β-1,3-Glucan binding protein (β-GBP) was purified from the haemolymph of Episesarma tetragonum by affinity chromatography with epoxy-activated laminarin-sepharose CL-6B column. E. tetragonum β-GBP exhibits a single band with a molecular weight of 100 kDa on SDS-PAGE and a pI of 5.9 in isoelectric focusing (IEF). The circular dichroism (CD) spectra result of E. tetragonum β-GBP indicates that the negative ellipticity bands near 220 nm and 208 nm correspond to the β-sheets in the secondary structure. Functional analysis results demonstrate that the purified E. tetragonum β-GBP agglutinates fungal cells (Candida albicans) containing β-glucan. This recognition and binding specificity leads to the activation of the prophenoloxidase (ProPO) cascade and enhance the phenoloxidase (PO) activity in a dose-dependent manner. Our finding discloses new insights in the ProPO activation and fungal agglutination of purified E. tetragonum β-GBP. It seems to play a significant role in microbial uncovering mechanism in invertebrates.
authors.affiliation: Crustacean Molecular Biology and Genomics Lab, Department of Animal Health and Management, Alagappa University, Karaikudi 630 004, Tamil Nadu, India.
authors.forename: Jeyachandran
authors.initials: J
authors.lastname: Sivakamavalli
authors.affiliation: Crustacean Molecular Biology and Genomics Lab, Department of Animal Health and Management, Alagappa University, Karaikudi 630 004, Tamil Nadu, India. Electronic address: vaseeharanb@gmail.com.
authors.forename: Baskaralingam
authors.initials: B
authors.lastname: Vaseeharan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003386:Brachyura / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D002352:Carrier Proteins / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification / Q000648:ultrastructure; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D004591:Electrophoresis, Polyacrylamide Gel; D006458:Hemolymph / Q000737:chemistry; D037102:Lectins / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D047071:beta-Glucans / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D037102:Lectins; D047071:beta-Glucans; C037937:glucan-binding proteins; C033363:beta-1,3-glucan
keywords: Agglutination; Episesarma tetragonum; Innate immunity; Prophenoloxidase; β-Glucan binding protein