Characterization and Preliminary Application of a Novel Lipoxygenase from Enterovibrio norvegicus

Abstract

Lipoxygenases have proven to be a potential biocatalyst for various industrial applications. However, low catalytic activity, low thermostability, and narrow range of pH stability largely limit its application. Here, a lipoxygenase (LOX) gene from Enterovibrio norvegicus DSM 15893 (EnLOX) was cloned and expressed in Escherichia coli BL21 (DE3). EnLOX showed the catalytic activity of 40.34 U mg−1 at 50 °C, pH 8.0. Notably, the enzyme showed superior thermostability, and wide pH range stability. EnLOX remained above 50% of its initial activity after heat treatment below 50 °C for 6 h, and its melting point temperature reached 78.7 °C. More than 70% of its activity was maintained after incubation at pH 5.0–9.5 and 4 °C for 10 h. In addition, EnLOX exhibited high substrate specificity towards linoleic acid, and its kinetic parameters of Vmax, Km, and Kcat values were 12.42 mmol min−1 mg−1, 3.49 μmol L−1, and 16.86 s−1, respectively. LC-MS/MS analysis indicated that EnLOX can be classified as 13-LOX, due to its ability to catalyze C18 polyunsaturated fatty acid to form 13-hydroxy fatty acid. Additionally, EnLOX could improve the farinograph characteristics and rheological properties of wheat dough. These results reveal the potential applications of EnLOX in the food industry.

Plasma Bubbling of Soymilk: Impact on Allergenicity, Antinutritional Factor, and E-Nose-Retrieved Sensory Characteristics

“…Aanangi et al study on mung beans showed higher LOX activity between the pH ranges of 6.0–7.0. Similar effects were observed in the Zhang et al study, where the LOX relative activity increased linearly from ∼0 to around 100% with a pH increase from 3.5 to 8.0, respectively. However, in the current study, an initial decline in LOX activity was observed, possibly due to the denaturation of a small portion of LOX by plasma reactive species.…”

Enhanced Thermostability and Molecular Insights for l-Asparaginase from Bacillus licheniformis via Structure- and Computation-Based Rational Design

“…10 Enzymes with combination properties of activity in a mild temperature, superior thermal stability, good substrate specificity, and high enzyme activity are required for industrial applications. 50 Therefore, it is necessary to make molecular modifications to enzymes with existing properties. A rational design is often applied to predict important amino acid residue sites in order to improve the efficiency and feasibility of protein engineering.…”

“…Although the mining of thermophilic and mesophilic enzymes with good thermostability solved the problem of short half-lives, the inactivity of thermophilic enzymes at mild temperatures and the low activity or poor substrate specificity of mesophilic enzymes that have good thermostability limited their industrial applications . Enzymes with combination properties of activity in a mild temperature, superior thermal stability, good substrate specificity, and high enzyme activity are required for industrial applications . Therefore, it is necessary to make molecular modifications to enzymes with existing properties.…”

Bacterial lipoxygenases are associated with host-microbe interactions and may provide cross-kingdom host jumps

“…The data for all bacteria included in this statistical analysis are provided in Table S3. The bar at the right shows total binding site bottom volumes of experimentally characterized LOXs [147,[149][150][151][152][153][154] along with their activities. "Human-related" and "plant-related" groups correspond (ω-6)-LOX activity while "marine-related" group is shifted towards (ω-12)-LOX activity.…”

“…Compared with the binding site bottom volumes of experimentally characterized LOXs [147,[149][150][151][152][153][154] (calculated by the same method), the "human-related" and "plant-related" LOX groups appear to correspond to (ω-6)-LOXs. The Pseudomonas aeruginosa and Burkholderia thailandensis LOXs (both belonging to the "human/vertebrate" group in our statistics) have total binding site bottom volumes (472.2×10 -3 nm 3 and 475×10 -3 nm 3 , respectively) near to the mean of the "human-related" group.…”