Thermostability modification and simulated application of acidic catalase
摘要
Catalase plays a significant role in improving animal intestinal health and growth performance; however, its industrial application in feed is largely limited by poor thermostability and low acid tolerance. We identified an acid-resistant catalase from Talaromyces pinophilus and improved its thermal stability. We integrated multiple thermal stability design strategies, constructed a mutation library using algorithms from different design platforms, and further refined the library with computational tools. This approach successfully generated the combinatorial mutant M3 (E38Q/S69P/S187A). Its half-life at 80 °C increased by 2.64 times, and two fold increase in half life at 90 ℃, while the specific activity remained unchanged. Molecular dynamics simulations show that this mutational strategy can significantly enhance the thermal stability of catalase through a cascading effect of ‘local rigidity enhancement—global conformational compaction—hydrophobic core stabilization’. Additionally, under simulated high-temperature and gastric acid conditions, the mutant strain demonstrated a high capacity for decomposing H2O2, significantly enhancing its practical value for use in animal feed.
Graphical abstract