Isolation and Biophysical Characterization of Lipoxygenase-1 from Soybean Seed, a Versatile Biocatalyst for...

Lipoxygenases are enzymes found in plants, mammals, and other organisms that catalyse the hydroperoxidation of polyunsaturated fatty acids, such as arachidonic, linoleic, and linolenic acids. They have attracted a lot of attention as molecular targets for industrial and biomedical applications, due to their implication in key biological processes, such as plant development and defence, cell growth, as well as immune response and inflammation. Soybean (Glycine max) lipoxygenase (LOX) is a versatile biocatalyst used in biotechnology, pharmaceutical, and food industries. sLOX1, a soybean LOX isoform, is central in various industrial applications; thus, it is of particular interest to develop an efficient sLOX1 isolation process, control its activity, and leverage its potential as an effective industrial biocatalyst, tailoring it to a specific desired outcome. In this study, sLOX1 was extracted and purified from soybean seeds using an optimized protocol that yielded an enzyme preparation with higher activity compared to the commercially available lipoxygenase. Comprehensive biophysical characterization employing dynamic and electrophoretic light scattering, fluorescence, and Fourier-transform infrared spectroscopies revealed that sLOX1 exhibits remarkable structural and functional stability, particularly in sodium borate buffer (pH 9), where it retains activity and integrity up to at least 55 °C and displays minimal aggregation under thermal, ionic, and temporal stress. In contrast, sLOX1 in sodium phosphate buffer (pH 6.8) remained relatively stable against ionic strength and time but showed thermally induced aggregation above 55 °C, while in sodium acetate buffer (pH 4.6), the enzyme exhibited a pronounced aggregation tendency under all tested conditions. Overall, this study provides physicochemical and stability assessments of sLOX1. The combination of enhanced catalytic activity, high purity, and well-defined stability profile across diverse buffer systems highlights sLOX1 as a promising and adaptable biocatalyst for industrial applications, offering valuable insights into optimizing lipoxygenase-based bioprocesses.