Abstract: Homology modeling was used to predict the 3D structure of lipoxygenase from Anabaena sp. PCC 7160 (Ana-LOX) and to simulate its motion trajectory in aqueous solution by molecular dynamics simulation at 298 and 320 K,respectively. After root mean square deviation (RMSD) and root mean square fluctuation (RMSF) values were calculated,thermal stability was evaluated based on the RMSF value. Force analysis was also performed to predict the unstable region.Results indicated that the T94, I96, and A325 to Q327 areas of Ana-LOX were flexible and they played a crucial role in thethermal instability of Ana-LOX. The half-life of I96V mutant constructed by site-directed mutagenesis increased 2.5 foldscompared with that of the wild-type enzyme, confirming the validity of the prediction. Our research can provide a theoreticalbasis for the improvement of the thermal stability of lipoxygenase.

Key words: gelatin peptide, calcium, chelating, response surface optimization, simulated gastrointestinal digestion