A Novel Cold-Adapted and Heat-Resistant Alginate Lyase: Unveiling Its Characteristics and Mechanism of Thermostability.
TL;DR
A novel alginate lyase is identified, PpAly7A (26.75% sequence identity), which adapts to various pH, temperatures, salt concentrations, metal ions, and surfactants, and provides a viable molecular template for the rational design of thermostable industrial enzymes.
Abstract
Alginate lyases are important for producing bioactive oligosaccharides and combating Pseudomonas aeruginosa biofilms, demonstrating significant application potential in medicine, food, industry, and other sectors. However, few cold-adapted enzymes with high thermostability exist. Here, we identified a novel alginate lyase, PpAly7A (26.75% sequence identity), which adapts to various pH, temperatures, salt concentrations, metal ions, and surfactants. PpAly7A effectively disrupts P. aeruginosa PAO1 biofilms (36.51% removal) and exhibits exceptional thermostability (half-life 4.39 days at 50 °C). Site-directed mutagenesis and molecular dynamics simulations revealed that synergistic interactions among disulfide bonds, proline residues, salt bridges, and hydrogen bond networks maintain thermostability by enhancing global stability and compactness. Notably, the E180Q mutation further extends the half-life to 7.25 days while retaining most catalytic activity, demonstrating a favorable activity-stability trade-off. This study deepens the understanding of the structure-function relationships of enzymes and provides a viable molecular template for the rational design of thermostable industrial enzymes.