General protein binding

General protein binding refers to the non-specific association of small molecules or drugs with various proteins, most commonly plasma proteins such as human serum albumin and alpha-1-acid glycoprotein. This term does not describe a specific therapeutic target, receptor, or enzyme, but rather a pharmacological phenomenon that influences a drug's distribution, metabolism, and excretion. In drug discovery and database curation, this label is often used as a catch-all for assays where a specific molecular target was not identified or where the interaction is inherently non-selective. Because it lacks a discrete biological site of action and a specific role in disease pathophysiology, it is considered an incorrect or overly generic designation for a drug target. Understanding these interactions is vital for predicting the free fraction of a drug in systemic circulation, which is the portion available to exert a therapeutic effect at actual targets. High non-specific binding can lead to significant therapeutic challenges, including the need for higher dosing and an increased potential for displacement-based drug-drug interactions.

Other names

Non-specific protein bindingPlasma protein bindingSerum protein bindingTotal protein binding

Non-specific physicochemical interaction