Sequence-Structure Combination Strategy Enables Discovery of a Novel Transglutaminase from Krasilnikovia cinnamomea and Computational Analysis

Transglutaminase (TGase) is a widely utilized biocatalyst in the food industry, where it catalyzes the cross-linking of proteins in protein-rich foods, leading to improved texture and enhanced functional properties. Currently, commercially available TGases are derived from Streptomyces species. To expand the industrial application potential of TGase, this study employed a combined sequence- and structure-based strategy to identify a novel TGase from Krasilnikovia cinnamomea (KcTG). The enzyme was successfully heterologously expressed in Escherichia coli, exhibiting an optimal temperature of 60 °C and a maximum specific activity of 42.17 U/mg, outperforming SmTG. Furthermore, KcTG demonstrated efficient cross-linking of soy protein isolate, positioning it as a promising candidate for future industrial TGase enzyme preparations. This study also integrated computational tools to analyze the structural characteristics of KcTG based on surface net charge and hydrophobicity. Additionally, molecular dynamics (MD) simulations were employed to investigate its stability and catalytic performance.