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Kinetic parameters for heat-induced denaturation of lactoferrin under different conditions were determined over a temperature range 72-85°C. Denaturation of lactoferrin could be described by first-order reaction kinetics. Lactoferrin is denatured more rapidly in its apo form than in the iron-saturated form. Both apolactoferrin and iron-saturated lactoferrin are more heat-sensitive when treated in milk than in phosphate buffer. Values of change in enthalpy of activation of lactoferrin denaturation are high which indicates that a large number of bonds are broken. The association of lactoferrin with 8-lactoglobulin does not significantly influence the change in enthalpy of activation of lactoferrin denaturation.

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PurposeThe prevalence of HCV infection has increased during recent years and the incidence reach 3% of the world's population, and in some countries like Egypt, may around 20%. The developments of effective and preventive agents are critical to control the current public health burden imposed by HCV infection. Lactoferrin in general and camel lactoferrin specifically has been shown to have a compatitive anti-viral activity against hepatitis C virus (HCV). The purpose of this study was to examine and compare the anti-infectivity of native human, camel, bovine and sheep lactoferrin on continuous of HCV infection in HepG2 cells.Material and methodsUsed Lfs were purified by Mono S 5/50 GL column and Superdex 200 5/150 column. The purified Lfs were evaluated in two ways; 1. the pre-infected cells were treated with the Lfs to inhibit intracellular replication at different concentrations and time intervals, 2. Lfs were directly incubated with the virus molecules then used to cells infection. The antiviral activity of the Lfs were determined using three techniques; 1. RT-nested PCR, 2. Real-time PCR and 3. Flowcytometric.ResultsHuman, camel, bovine and sheep lactoferrin could prevent the HCV entry into HepG2 cells by direct interaction with the virus instead of causing significant changes in the target cells. They were also able to inhibit virus amplification in HCV infected HepG2 cells. The highest anti-infectivity was demonstrated by the camel lactoferrin.ConclusioncLf has inhibitory effect on HCV (genotype 4a) higher than human, bovine and sheep lactoferrin.

beta-Lactoglobulin isolated from milk of cow, sheep, and goat had about 0.5 mol of fatty acids bound per mol of monomer protein. Fatty acids, mainly palmitic and oleic acids, were the major components (about 75% of total lipids). Albumin isolated from the same samples had about 4.5 mol of fatty acids bound per mol of protein. These two proteins were the only whey proteins able to bind labeled fatty acids in vitro. Interaction of beta-lactoglobulin and albumin with insolubilized fatty acids showed some differences, suggesting different structures of the respective fatty acid binding sites.