General negatively charged proteins and colloidal particles

General negatively charged proteins and colloidal particles refer to a broad category of biological and chemical entities that exhibit a net negative surface charge at physiological pH. This group encompasses a wide range of substances, including bile acids, phosphate ions, and various plasma proteins such as albumin (NIH, StatPearls). In a therapeutic context, these entities are often the focus of non-specific sequestration strategies rather than traditional lock-and-key molecular targeting. Cationic drugs, such as bile acid sequestrants and phosphate binders, utilize electrostatic interactions to bind these anionic species in the gastrointestinal tract, preventing their absorption into the bloodstream (PubMed, PMC1570803). For instance, colestyramine binds bile acids to lower systemic cholesterol, while sevelamer is employed to control phosphate levels in patients with chronic kidney disease. Because this target is a physical property shared by many molecules, drugs acting on it often lack high specificity, leading to potential interactions with other negatively charged nutrients or medications. This lack of specificity can result in safety concerns such as the malabsorption of fat-soluble vitamins. Consequently, while these interactions are clinically significant, they represent a class-based physical interaction rather than a specific protein-ligand binding event.

Other names

Anionic proteinsNegatively charged macromoleculesPolyanionic colloidsAnionic substrates

Non-specific electrostatic binding and sequestration of anionic species to inhibit gastrointestinal absorption or facilitate excretion.