Human plasma proteins (HPP)

Human plasma proteins represent the vast and complex proteome found within the intravascular compartment, comprising thousands of distinct proteins such as albumin, globulins, and fibrinogen (Anderson & Anderson, 2002). These proteins perform essential physiological functions, including the maintenance of colloid osmotic pressure, pH buffering, transport of endogenous and exogenous substances, and mediation of the immune response and coagulation cascades (StatPearls, 2023). In pharmacology, human plasma proteins are primarily characterized by their role in plasma protein binding (PPB), where drugs reversibly bind to proteins like albumin or alpha-1-acid glycoprotein, thereby limiting the concentration of free drug available for tissue distribution and therapeutic action (Smith et al., 2010). Alterations in the concentration or composition of these proteins, often seen in hepatic or renal diseases, can lead to significant changes in drug pharmacokinetics and clinical outcomes (NIH, 2022). While the collective plasma proteome is not a single therapeutic target, individual proteins within this group are frequently utilized as biomarkers or targeted for replacement therapy in conditions like hemophilia or primary immunodeficiency (PubMed, 2021).

Other names

Blood proteinsSerum proteinsPlasma proteomeCirculating proteins

Drugs interact with human plasma proteins primarily through reversible non-specific binding, which sequesters the drug in the vascular compartment and determines the pharmacologically active free fraction (Smith et al., 2010). Specific proteins like albumin and alpha-1-acid glycoprotein serve as the primary reservoirs for acidic and basic drugs, respectively (StatPearls, 2023).