Characterization of a Novel Carrageenan-Specific Carbohydrate- Binding Module: a Promising Tool for the In Situ Investigation of Carrageenan

Carrageenan is a commercially important polysaccharide widely applied in the food industry. Specific probes are critical tools for the in situ investigation of polysaccharides, whereas the carrageenan-specific probes are limited at present. Carbohydrate-binding modules (CBMs) could serve as specific probes for the in situ investigation of polysaccharides. In the present study, an unknown function module from the x-carrageenase Cgk16A was cloned and expressed in Escherichia coli. The expressed protein Cgk16A-CBM92 could specifically bind to carrageenan. Its novelty sheds light on a new CBM family (CBM92) as the founding member. Furthermore, a fluorescent probe was successfully constructed by fusing Cgk16A-CBM92 with a green fluorescent protein. The application potential of Cgk16A-CBM92 as a probe served in the in situ visualization of carrageenan was evaluated. The discovery of Cgk16A-CBM92 provided a promising tool for the in situ investigation of carrageenan.

Automated summary

In this study, an unknown function module Cgk16A-CBM92 from Cgk16A was cloned and expressed, and it was found to specifically bind to carrageenan. This discovery provides a potential tool for the in situ investigation of carrageenan.