albumine

Albumin, commonly called albumine in several languages, is a family of soluble globular proteins that are highly abundant in blood plasma. In humans the principal form is human serum albumin (HSA). Albumins are synthesized in the liver by hepatocytes and circulate in the bloodstream, contributing the majority of plasma protein mass and a major portion of the colloid osmotic pressure that retains fluid in the vascular compartment.

Human serum albumin is a single polypeptide chain of 585 amino acids with a molecular weight of about 66.5 kDa. It contains 17 disulfide bonds and one free thiol group on cysteine-34, giving it redox activity and binding capacity. The protein has multiple binding sites and acts as a carrier, binding and transporting a wide range of endogenous and exogenous compounds, including long-chain fatty acids, bilirubin, hormones, drugs, and metal ions. Its binding properties influence the pharmacokinetics of many medications.

In health, albumin maintains oncotic pressure and serves as a reservoir of amino acids and a scavenger of reactive species. Clinically, albumin is used as a plasma volume expander in certain medical settings. Bovine serum albumin (BSA) is widely used in laboratory research as a stabilizer and protein standard, while recombinant or purified albumin is used in biotech and medicine. Low serum albumin (hypoalbuminemia) can reflect liver disease, malnutrition, kidney disease (nephrotic syndrome), or inflammatory states, and may lead to edema or contribute to complications; elevated levels can occur with dehydration or high protein intake. Albumin concentrations are routinely measured as part of liver and kidney function assessment.