alpha-Lactalbumin species variation, HAMLET formation, and tumor cell death.

Abstract

HAMLET (human alpha-lactalbumin made lethal to tumor cells) is a tumoricidal complex of apo alpha-lactalbumin and oleic acid, formed in casein after low pH treatment of human milk. This study examined if HAMLET-like complexes are present in casein from different species and if isolated alpha-lactalbumin from those species can form such complexes with oleic acid. Casein from human, bovine, equine, and porcine milk was separated by ion exchange chromatography and active complexes were only found in human casein. This was not explained by alpha-lactalbumin sequence variation, as purified bovine, equine, porcine, and caprine alpha-lactalbumins formed complexes with oleic acid with biological activity similar to HAMLET. We conclude that structural variation of alpha-lactalbumins does not preclude the formation of HAMLET-like complexes and that natural HAMLET formation in casein was unique to human milk, which also showed the highest oleic acid content.

• Authors: Jenny Pettersson, Ann-Kristin Mossberg, Catharina Svanborg
• Journal: Biochemical and biophysical research communications (Biochem Biophys Res Commun) Vol. 345 Issue 1 Pg. 260-70 (Jun 23 2006) ISSN: 0006-291X [Print] United States
• PMID: 16678133 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Caseins
• HAMLET complex, human
• Oleic Acids
• Oleic Acid
• Lactalbumin

Topics

• Amino Acid Sequence
• Animals
• Apoptosis (drug effects)
• Caseins (chemistry, pharmacology)
• Cattle
• Cell Line, Tumor
• Dose-Response Relationship, Drug
• Horses
• Humans
• Lactalbumin (chemistry, pharmacology)
• Lymphoma (pathology)
• Mice
• Milk (chemistry)
• Molecular Sequence Data
• Oleic Acid (chemistry, pharmacology)
• Oleic Acids (chemistry, pharmacology)
• Sequence Homology, Amino Acid
• Species Specificity
• Swine