The ALB gene provides instructions for creating albumin, the most abundant protein found in human blood. This protein plays a critical role in regulating blood plasma colloid osmotic pressure. Interestingly, it has additional functions including:
Transport: Albumin acts as a carrier protein for a variety of molecules, both those naturally produced by the body such as hormones (e.g. thyroxine) and fatty acids as well as those introduced from external sources such as ions (Zn/Ca/Mg), metabolites, and drugs.
- Albumin is conserved across vertebrates but exhibits significant variability across species, with differences between albumin domains reaching 70-80%. This remarkable evolutionary diversity is likely attributed to the development of specific binding properties tailored to accommodate new ligands—hormones, metabolites, and toxins—as species evolved.
Esterase: Albumin has esterase-like activity, exhibiting the capability to interact with a broad spectrum of substrates.
Bacterial Growth Inhibition: Albumin can bind to enterobactin, a bacterial siderophore, and hinder the iron uptake of E.coli from ferric transferrin. This interaction may limit iron utilization and restrict the growth of certain enteric bacteria, including E.coli. However, it's noteworthy that albumin does not inhibit iron uptake mediated by the bacterial siderophore aerobactin.
Immune modulation: A peptide derived from albumin, EPI-X4, inhibits the CXCR4 chemokine receptor
