Albumin is a globular protein. Serum albumin is a member of the multigene protein family. Human serum albumin (HSA) consists of three homologous domains (I-III) that form a heart-shaped structure. Each domain is a result of two subdomains called A and B. Bovine serum albumin (BSA) has a structure that is very similar to HSA as it has a heart-shaped structure that has three homologous domains (I-III) and each domain has three sub-domains.
Albumin is a highly soluble, multifunctional and major circulating plasma protein. It plays a role in physiological and pharmacological areas. Albumin participates in the transport of metals, cholesterol, hormones, bile pigments, drugs, and fatty acids. It regulates osmotic pressure and distributes fluids between various compartments. In addition, plasma albumin exhibits anti-oxidant effects to minimize oxidative stress. Albumin attributes to the major portion of total serum antioxidant properties.