Alpha-Lactalbumin

Alpha-Lactalbumin

Alpha-Lactalbumin is a protein that is a major component of the whey protein in mammalian milk. It is synthesized in the mammary gland and is a key player in the production of lactose, the primary carbohydrate found in milk.

Structure

Alpha-Lactalbumin is a small globular protein with a molecular weight of approximately 14,200 daltons. It is composed of 123 amino acids and contains four disulfide bonds, which contribute to its compact, stable structure. The protein has a single polypeptide chain and is rich in alpha-helix structures.

Function

The primary function of alpha-lactalbumin is to regulate the production of lactose in the mammary gland. It does this by binding to the enzyme beta-galactosyltransferase, altering its substrate specificity and enabling it to synthesize lactose from glucose and galactose. This is a crucial process in the production of milk, as lactose is the primary source of energy for newborn mammals.

In addition to its role in lactose synthesis, alpha-lactalbumin also has several other functions. It has been shown to have antimicrobial properties, and it may play a role in the immune response. It also has potential anticancer properties, as it can induce apoptosis in certain types of cancer cells.

Clinical Significance

Due to its potential anticancer properties, alpha-lactalbumin has been the subject of numerous studies investigating its potential use in cancer treatment. In particular, a complex of alpha-lactalbumin and oleic acid, known as HAMLET (Human Alpha-lactalbumin Made Lethal to Tumor cells), has been shown to selectively kill cancer cells without harming healthy cells.

Alpha-lactalbumin is also of interest in the field of infant nutrition. As a major component of human milk, it is believed to contribute to the superior nutritional quality of breast milk compared to formula. Studies have shown that infants fed with formula supplemented with alpha-lactalbumin have improved growth and cognitive development compared to those fed with standard formula.

See Also

• Beta-lactoglobulin
• Casein
• Lactose
• Whey protein