Purification and characterization of a 1,3-β-D-glucan recognition protein from Antheraea pernyi larve that is regulated after a specific immune challenge

Pattern recognition receptors are known to participate in theactivation of Prophenoloxidase system. In this study, a1,3-β-D-glucan recognition protein was detected for the firsttime in Antheraea pernyi larvae (Ap-βGRP). Ap-βGRP waspurified to 99.9% homogeneity from the hemolymph usingtraditional chromatographic methods. Ap-βGRP specificallybind 1,3-β-D-glucan and yeast, but not E. coli or M. luteus.The 1,3-β-D-glucan dependent phenoloxidase (PO) activity ofthe hemolymph inhibited by anti-Ap-βGRP antibody could berecovered by addition of purified Ap-βGRP. These resultsdemonstrate that Ap-βGRP acts as a biosensor of 1,3-β-Dglucanto trigger the Prophenoloxidase system. A trace mountof 1,3-β-D-glucan or Ap-βGRP alone was unable to trigger theproPO system, but they both did. Ap-βGRP was specificallydegraded following the activation of proPO with 1,3-β-Dglucan.These results indicate the variation in the amount ofAp-βGRP after specific immune challenge in A. pernyihemolymph is an important regulation mechanism to immuneresponse. [BMB Reports 2013; 46(5): 264-269]