Synonyms and Functions of Alpha-Lactalbumin
In biochemistry, many proteins have official gene symbols and other names that describe their function. When asking what is another name for alpha-lactalbumin, several terms can be used depending on the context.
- LALBA: This is the official gene symbol for alpha-lactalbumin in humans.
- Lactose synthase B protein: This name directly reflects its biological function as the regulatory subunit of the lactose synthase enzyme, which synthesizes lactose.
- Lysozyme-like protein 7 (LYZL7): This name points to the structural similarity alpha-lactalbumin shares with lysozymes, though their functions differ.
The Importance of Alpha-Lactalbumin in Breast Milk
As the most abundant whey protein in human milk, alpha-lactalbumin plays a vital role in infant nutrition. It provides a high concentration of essential amino acids, such as tryptophan, which is a precursor for the neurotransmitter serotonin, important for mood and sleep regulation. The protein's function in lactose synthesis also helps produce lactose, the main carbohydrate in milk that provides energy to the infant. Additionally, alpha-lactalbumin contains bioactive peptides with potential antimicrobial and immunomodulatory properties that support gut health and aid in protecting against infections.
Comparison: Alpha-Lactalbumin vs. Beta-Lactoglobulin
While often mentioned together as the two major whey proteins, alpha-lactalbumin (α-La) and beta-lactoglobulin (β-Lg) have distinct properties and are present in different proportions across mammalian milk.
| Feature | Alpha-Lactalbumin (α-La) | Beta-Lactoglobulin (β-Lg) |
|---|---|---|
| Abundance in Human Milk | Most abundant whey protein (10–20% of total protein). | Absent in human breast milk. |
| Abundance in Cow Milk | Second most abundant whey protein (around 3% of total protein). | Most abundant whey protein (65% of total whey protein). |
| Function | Regulatory subunit for lactose synthase, enhances lactose synthesis. | Lipocalin protein, potentially involved in binding and transporting hydrophobic molecules. |
| Amino Acid Profile | Rich in tryptophan and cysteine, highly digestible. | Has a different amino acid profile; can be allergenic for some individuals. |
| Heat Stability | Relatively heat-stable when bound to calcium. | Forms gels and denatures easily upon heating, a factor in dairy processing. |
Other Health Benefits and Applications
Alpha-lactalbumin's nutritional value extends beyond infancy, with applications in adult nutrition and wellness products. Its rich tryptophan content is utilized in supplements aimed at improving sleep quality and managing stress. The protein's ability to bind with certain minerals, such as calcium and zinc, may enhance their absorption. Additionally, research has explored the cytotoxic properties of a variant of alpha-lactalbumin, known as HAMLET, which has shown promise in targeting tumor cells.
Processing and Commercial Availability
Commercial alpha-lactalbumin is typically derived from bovine milk whey using advanced separation techniques like membrane filtration and ion exchange chromatography. These methods allow for the isolation of highly purified alpha-lactalbumin for use in infant formula, functional foods, and nutritional supplements. The development of these technologies has made it possible to enrich formulas to more closely match the nutritional composition of human breast milk, offering benefits to formula-fed infants.
Conclusion
Alpha-lactalbumin, also known by its gene symbol LALBA and its functional name lactose synthase B protein, is a critical whey protein with numerous health benefits. Its role in lactose synthesis, provision of essential amino acids like tryptophan, and unique bioactive properties make it invaluable in both infant and adult nutrition. As research continues to uncover its diverse functionalities, alpha-lactalbumin is expected to be further integrated into advanced nutritional products for promoting overall health and wellbeing. Understanding its various names, from LALBA to lactose synthase B protein, helps clarify its specific biochemical role and importance.
