Isolation of human lactoferrin by affinity chromatography using insolubilized bovine beta-lactoglobulin

The Multifaceted Roles of Bovine Lactoferrin: Molecular Structure, Isolation Methods, Analytical Characteristics, and Biological Properties

Bovine lactoferrin (bLF) is widely known as an iron-binding glycoprotein from the transferrin family. The bLF molecule exhibits a broad spectrum of biological activity, including iron delivery, antimicrobial, antiviral, immunomodulatory, antioxidant, antitumor, and prebiotic functions, thereby making it one of the most valuable representatives for biomedical applications. Remarkably, LF functionality might completely differ in dependence on the iron saturation state and glycosylation patterns. Recently, a violently growing demand for bLF production has been observed, mostly for infant formulas, dietary supplements, and functional food formulations. Unfortunately, one of the reasons that inhibit the development of the bLF market and widespread protein implementation is related to its negligible amount in both major sources─colostrum and mature milk. This study provides a comprehensive overview of the significance of bLF research by delineating the key structural characteristics of the protein and elucidating their impact on its physicochemical and biological properties. Progress in the development of optimal isolation techniques for bLF is critically assessed, alongside the challenges that arise during its production. Furthermore, this paper presents a curated list of the most relevant instrumental techniques for the characterization of bLF. Lastly, it discusses the prospective applications and future directions for bLF-based formulations, highlighting their potential in various fields.

Survey of Salty and Sweet Whey Composition from Various Cheese Plants in Wisconsin

Salty whey is currently underutilized in the dairy industry because of its high salt content and increased processing and disposal costs. Salty whey accounts for 2 to 5% of the total whey generated during Cheddar and other dry-salted cheese manufacture. Because relatively little information is available on salty whey, this study was conducted to determine the range of compositional components in salty whey from commercial cheese plants. Gross compositional differences in percent protein, salt, solids, and fat between sweet whey and salty whey from various dry-salted cheeses from 8 commercial plants were determined. Differences between individual whey protein compositions were determined using sodium dodecyl sulfate-PAGE. Average total solids, fat, and salt content were significantly greater in the salty whey compared with the corresponding sweet whey. True protein was reduced in salty whey although great variability existed among samples. Individual whey proteins identified included lactoferrin (Lf), BSA, immunoglobulin G, beta-lactoglobulin, and alpha-lactalbumin. Salty whey showed an increase in Lf content and a decrease in alpha-lactalbumin and beta-lactoglobulin content when compared with sweet whey. Salty whey may be a source of Lf, potentially increasing its value to whey processors. However, the compositional assessments showed that commercial salty whey is a highly variable waste stream.

Effect of bovine milk antigens and egg lysozyme on the binding of 59Fe-lactoferrin to platelet plasma membranes

1. Platelets bind specifically to lactoferrin. A significant similarity between human lactoferrin and some bovine milk proteins has been established. 2. Because of the structural homology of lactoferrin and cows milk proteins they are able to influence lactoferrins regulatory function on the level of its binding to membrane receptors on platelets. 3. An inhibitory effect of bovine alpha-lactalbumin and of beta-lactoglobulin on lactoferrin-receptor interaction was shown. 4. Bovine alpha-lactalbumin competes with lactoferrin for the binding sites. 5. Scatchard plot analysis of data shows one binding site for lactoferrin in the presence of alpha-lactalbumin with an affinity constant, Ka = 0.46 x 10(9) mol/l and 335 receptors/cell. 6. The inhibitory effect of beta-lactoglobulin reaches 62% and is different for the common fraction beta-lactoglobulin and the genetic variants beta-lactoglobulin A and B. 7. beta-lactoglobulin does not compete with lactoferrin for the membrane receptors. 8. Bovine casein and egg lysozyme stimulate 59Fe-lactoferrin binding to the receptors. The mechanism of these effects is still unknown. 9. Tested alimentary antigens are able to interact with lactoferrin and also with some platelet membrane structures. 10. Established changes in lactoferrin binding to the platelet membrane might be in relation to lactoferrins regulatory function and (or) eliminating mechanisms of these alimentary antigens.

High-performance liquid chromatographic separation of human apolactoferrin and monoferric and diferric lactoferrins

A simple chromatographic separation of the different molecular forms of human milk lactoferrin according to their iron contents is described. The appropriate conditions were developed with a Mono-S cation-exchange column linked to an automated Urtrochrom GTi system. The pure lactoferrin with different iron binding (apolactoferrin, monoferric lactoferrin and diferric lactoferrin) separated into three peaks. The three peaks were eluted from the Mono-S column with 0.88, 0.97 and 1.05 M sodium chloride in 10 mM phosphate buffer (pH 7.0).

Different profiles of induced cotton effects of human and bovine lactoferrin by cibacron blue F3GA binding

1. The properties of complex formation of lactoferrin with Cibacron Blue F3GA dye have been studied by circular dichroic spectral analyses. The Cotton effects were induced by the interaction of lactoferrin with the dye and occurred in the wavelength range from 300 to 450 nm. 2. The patterns of changes in circular dichroic spectra of lactoferrin induced by the dye were different in bovine and human lactoferrin. 3. Iron ions bound to lactoferrin affected the profiles of induced Cotton effects in human lactoferrin but not in bovine lactoferrin. 4. While the dye bound co-operatively to human apo-lactoferrin, such co-operativeness was not observed in iron-saturated human lactoferrin.