Studies On The Isolation,antibacteria,enhancement For Iron Absorption Of Lactoferrin

Lactoferrin(LF),an iron-binding glycoprotein ,Mr77000 ?2000Da, p1=8.0 ? 0.2,has many biological activities. We focus on the assay, isolation, heat stability, enhancement for intestinal iron absorption and antibacteria of LF. 1. Three immunochemical methods were developed as the foundation of other studies for LF. ELISA as a sensitive convenient method of assaying was performed with the minimum detectable concentration as 0.5mgIL and the linear range as 0.8OOmgIL. Simple immunodiffusion as another quantitative assaying is simple and quick. Double immunodiffusion in agar is highly specific for LF which depends on the precipitation by the antigen and antibody. 2. Bovine LF was isolated by CM-Sephadex C-SO column chromatography from defatted colostrum, using O.O2mol/L PBS(pH7.4) and a linear gradient of NaCL from 0 to 1 .Omol/L. 3. The influence of pH on the heat stability of LF was studied. Solutions of LF in buffer were adjusted to various pH values from 3.4 to 8.0 and heated at various temperature (65 C to 135 C). The heated simples were assayed for antigenic activity and bacteriostatic effect. These results indicate that LF is very stable at pH4.8 and high temperature. It was considered that heat condition of pH4.8 and temperature of 75 C was suitable as a practical method for pasteurization of LF 4. The solubility of ferric iron with LF was investigated in the presence of phosphate salts. LF could solubilize over a 60?0 fold molar equivalent of iron, which is much higher than the specific iron-binding ability of LF. 5. The influences of several physical conditions on the bacteriostatic effect of LF were investigated. It was found that the antibacteral activity increased with the increasing concentration of LF, and was influenced by the pH value also. The combined effect has been testified by the fact that the antibacteral activity enhanced with concurrent of IgY and LyS. ?? Postgraduate: Zhang Yinghua Food ScienceTutor f Professor Yang Tongzhou...