Diverse off-target and extracellular matrix proteins

This entry represents a heterogeneous collection of proteins frequently identified as off-targets or non-specific binding partners during the development of biologics and small molecules. The group includes keyhole limpet hemocyanin (KLH), a large, highly immunogenic multisubunit protein used as a carrier for haptens and as an adjuvant in vaccine research (Harris & Markl, 1999). It also encompasses critical extracellular matrix (ECM) components such as collagen type I, the most abundant structural protein in the human body, and decorin, a small leucine-rich proteoglycan involved in collagen fibrillogenesis and TGF-beta regulation (UniProt P02452, P21810). Additionally, the list includes von Willebrand factor (vWF), a multimeric glycoprotein essential for platelet adhesion and blood coagulation (UniProt P04275). In a pharmacological context, binding to these diverse proteins is generally considered a liability, as it indicates polyreactivity that can lead to 'sink effects,' where the drug is sequestered away from its intended target, resulting in poor bioavailability and unpredictable pharmacokinetic profiles (Rixon et al., 2020). Assessing a therapeutic candidate's interaction with these serum and matrix proteins is a vital step in safety profiling to minimize the risk of off-target toxicity and immunogenic responses.

Other names

Non-specific binding proteinsExtracellular matrix proteinsSerum proteinsOff-target proteinsPolyreactive targets

Non-specific binding or off-target interaction leading to drug sequestration, altered pharmacokinetics, or unintended immune activation.