inactivator

An inactivator is a substance or agent that reduces or abolishes the activity of a biological molecule, most commonly an enzyme, but also receptors or signaling proteins. Inactivation may be irreversible or reversible, and can occur by multiple mechanisms. Irreversible inactivators form covalent bonds or cause proteolytic cleavage, permanently disabling the target. Reversible inactivators bind through non-covalent interactions, inducing conformational changes or competition with substrates, leading to temporary loss of activity. Physical processes such as heat, pH shifts, or oxidative damage can also inactivate proteins, sometimes considered non-specific inactivators.

Targets include enzymes, receptors, and transcription factors. Examples in pharmacology include organophosphorus compounds that irreversibly inactivate serine hydrolases, and metal chelators or oxidants that inactivate metalloproteins. In research, inactivators are used to probe mechanism by selectively disabling a component. In industry, controlled inactivation serves to terminate enzyme activity in bioprocessing or sterilize materials.

Important distinctions: while inhibitors commonly refer to compounds reducing activity, inactivators often imply a more permanent loss or irreversible action, though terminology overlaps in some fields. Others use inactivator as a general term for any molecule that reduces function, including reversible inhibitors.

Safety and ethics: many inactivators are toxic or hazardous; proper handling and regulatory compliance are essential.