Characterization and Molecular Dynamics Simulation of a Lipase Capable of Improving the Functional Characteristics of an Egg-Yolk-Contaminated Liquid Egg White

• Published in: Foods 2023-11, Vol.12 (22), p.4098
• Main Authors: Xu, Linlin, Pan, Fei, Li, Yingnan, Liu, Huiqian, Wang, Chengtao
• Format: Article
• Language: English
• Subjects: Albumen; Amino acids; Bacteria; Baked goods; Conformation; Contamination; dynamic cross-correlation analysis; Dynamic stability; E coli; Enzymatic activity; Enzyme activity; Enzymes; Ethylenediaminetetraacetic acid; Foaming; foaming property; Hydrolysis; Lipase; Lipids; Molecular chains; Molecular dynamics; molecular dynamics simulation; Molecular weight; Particle size; Precipitation rate; Proteins; Simulation methods; Substrates; Temperature; Thermal stability; Triglycerides
• ISSN: 2304-8158; 2304-8158
• DOI: 10.3390/foods12224098

Lipase has great application potential in hydrolyzing residual yolk lipid in egg white liquid to restore its functional properties. In this study, a lipase gene from Bacillus subtilis was expressed in E. coli BL21 (DE3) and named Lip-IM. Results showed that although Lip-IM has stronger specificity for medium- and short-chain substrates than long-chain substrates (C16, C18), due to its excellent enzyme activity, it also has strong hydrolysis activity for long-chain substrates and maintained over 80% activity at 4–20 °C, but significantly reduced when the temperature exceeds 40 °C. The addition of 0.5% Lip-IM enhanced foaming ability by 26% (from 475 to 501%) and reduced liquid precipitation rate by 9% (from 57 to 48%). Furthermore, molecular dynamics (MD) simulations were run to investigate the conformational stability of Lip-IM at different temperatures. Results showed that Lip-IM maintained a stable conformation within the temperature range of 277–303 K. Fluctuations in the flexible area and backbone movement of proteins were identified as the main reasons for its poor thermal stability.