Serum albumin (ALB) (ALB)

Serum albumin is the most abundant protein in the plasma of humans and horses, playing a fundamental role in maintaining the colloid osmotic pressure required for proper fluid distribution between the intravascular and extravascular compartments [StatPearls, 2023]. Synthesized primarily in the liver, it functions as a versatile transport protein for a wide array of endogenous molecules, including fatty acids, bilirubin, and hormones, as well as numerous exogenous pharmacological agents [UniProt P02768]. The protein's structure, characterized by three homologous domains, contains specific binding sites—most notably Sudlow's sites I and II—that dictate the pharmacokinetic profile of many drugs by influencing their free concentration and systemic half-life [DrugBank DB00062]. In therapeutic contexts, human serum albumin is administered to treat conditions such as hypoalbuminemia, cirrhosis-related complications, and severe burns to restore blood volume [PubMed, 2021]. Additionally, it is a key component in drug delivery technologies, such as albumin-bound nanoparticles (e.g., nab-paclitaxel), which leverage the protein's natural transport mechanisms to improve the delivery of chemotherapeutic agents [Kratz, 2008]. Equine serum albumin is structurally similar and is frequently utilized in comparative biochemical studies and as a stabilizer in various veterinary and laboratory applications [UniProt P02770].

Other names

Human serum albuminEquine serum albuminHSAESAAlbuminALBU_HUMANALBU_HORSE

Serum albumin acts as a carrier protein that reversibly binds drugs, thereby regulating their distribution, metabolism, and excretion; it also functions as a therapeutic volume expander by increasing plasma oncotic pressure.