Human serum albumin and plasma lipoproteins

Human serum albumin (HSA) and plasma lipoproteins are the principal transport components of human blood, collectively responsible for the distribution of lipids, hormones, and xenobiotics. HSA is a monomeric protein that maintains plasma oncotic pressure and provides significant buffering capacity while binding a diverse array of ligands, including many acidic drugs (StatPearls, 2023). Plasma lipoproteins are multicomponent aggregates of lipids and specialized proteins (apolipoproteins) that facilitate the transport of hydrophobic cholesterol and triglycerides between tissues (NIH, 2022). In pharmacology, these entities are critical determinants of drug half-life and volume of distribution, as only the unbound fraction of a drug is typically pharmacologically active (PubMed, 2021). While they are not usually the primary targets of drug action, their levels and binding affinities are vital considerations in therapeutic dosing and the management of metabolic diseases like atherosclerosis (UniProt, 2024).

Other names

Plasma proteinsBlood transport proteinsSerum albuminLipoprotein particlesALBChylomicronsVLDLLDLHDL

These entities primarily function as transport vehicles rather than receptors; drugs interact via reversible binding to specific hydrophobic pockets (e.g., Sudlow sites I and II on albumin) or by being incorporated into the lipid core of lipoprotein particles for systemic distribution (PubMed, 2021).