Physicochemical and functional comparison of food-grade and precision-fermented bovine lactoferrin

This study provided a comprehensive physiochemical and functional comparison between food-grade, commercially available bovine lactoferrin (cLF) and two precision-fermented variants (pfLF_highFe and pfLF_lowFe) at varying iron saturation levels. LC-MS and FTIR/CD spectroscopy confirmed high purity and structural fidelity at primary and secondary levels, while UV-vis analysis revealed comparable molar absorptivity across all preparations. Fluorescence spectroscopy demonstrated tertiary structural variability with redshifts observed as a result of iron binding. Molecular weight (Mw) comparisons made using SDS-PAGE showed pfLF_highFe and pfLF_lowFe closely resembled cLF, while glycosylation analysis demonstrated very similar N-glycan compositions and site occupancy across low iron samples. The isoelectric points (pI) of pfLF_highFe and pfLF_lowFe were similar to cLF; however, varied slightly as a function of iron saturation, as did surface hydrophobicity (S0) measurements. Thermal denaturation analyses revealed characteristic behaviour of bovine lactoferrin preparations, with differences again observed according to the preparations iron saturation. Functional studies highlighted the iron chelating ability of native-LF preparations, cLF and pfLF_lowFe, and accompanying antimicrobial activity, but comparable interaction capacity with Lipid A (LPS) demonstrates preservation of structural and certain functional capabilities in precision-fermented bovine lactoferrin irrespective of iron saturation levels.