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E. D. BASTIAN and L. S. Ward. Research & Development, Glanbia Nutritionals, Inc., 450 Falls Ave., Ste. 255, Twin Falls, ID 83301 This presentation is a review of the biological activity of intact whey proteins and does not include peptides or fragments derived from whey proteins. We will cover beta-lactoglobulin, alpha-lactalbumin, kappa-casein fragment 106-169 (GMP 0, and lactoferrin. Beta-lactoglobulin, the most concentrated protein in whey is a retinol binding protein. Structural analysis shows how the inner, hydrophobic arrangement of amino acids provides the binding site for retinol, allowing the delivery of retinol in an aqueous system. Alpha-lactalbumin acts as a galactosyl-transferase enzyme modifier involved in lactose synthesis and is one of the predominant proteins in human breast milk, beta-lactoglobulin being conspicuously absent in such milk. Alpha-lactalbumin acts as a cystine delivery protein with potential for providing glutathione precursors. Alpha-lactalbumin with modified structure has been found by one research group to function in apoptosis of certain cancer cells. GMP has been reported to suppress appetite through stimulation of cholecystokinin (CCK). Early reports have been recently questioned and more research is needed to confirm such activity. GMP also has ability to impact interleukin-1 and interleukin-2, two cytokines involved in immune response, binding and receptor expression in T-cell lines. The lack of aromatic amino acids makes it an interesting protein source for phenylketonurics. Lactoferrin has been associated with a number of bioactivities including antimicrobial, antiviral, iron binding, and immune modulation. One example of the latter is in relation to skin irritants and the reduction of skin immune responses in the presence of lactoferrin.
Session 30, Whey proteins in foods: Past, present and future
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |