Binding Specificity of a New Artificial β-Glucan Recognition Protein and Its Application to β-Glucan Detection in Mushroom Extracts

β-1,3-D-glucan (BG) activates innate immunity and enhances immune responses. Fungi, such as mushrooms, produce a relatively large amount of BG, the structure and molecular weight of which varies depending on the species of fungi. This study was conducted to develop a detection probe for quantifying or detecting BG from fungi using BG-binding proteins. The binding properties of a new β-glucan recognition protein (BGRP) against various BGs were compared. With reference to the amino acid sequences of BGRP in insects, an artificial BGRP (supBGRP) was designed with higher production efficiency using gene recombination technology. SupBGRP was produced in Escherichia coli with high efficiency, and its reactivity with BG from fungi was the highest among the BG-binding proteins examined. SupBGRP exhibited high reactivity with 1,6-branched BG and will be useful for the quantification and detection of fungal BG.