Activatoren

Activatoren (activators) are substances or factors that increase the activity or response of a system. The term is used across disciplines such as biology, chemistry, and materials science, and the exact mechanism depends on the context.

In biology, activators are often discussed in two main contexts. Enzymatic activators are molecules that increase an enzyme’s catalytic activity, frequently by binding at sites other than the active site (allosteric activation). A well-known example is fructose-2,6-bisphosphate, which activates phosphofructokinase-1 and promotes glycolysis. Transcriptional activators are proteins that bind to DNA regulatory regions to raise the level of transcription, typically by recruiting RNA polymerase II and other components of the transcriptional machinery. Coactivators are non-DNA-binding proteins that facilitate transcription by bridging transcription factors and the transcriptional apparatus (for example, CBP/p300).

In chemistry and materials science, activators can refer to agents that enhance reaction rates or catalyst performance. In catalysis, activators may modify a catalyst to improve activity, selectivity, or stability, for instance by stabilizing reactive intermediates or generating an active site. In phosphor and luminescent materials, activators are dopant ions that create luminescence centers within a host lattice, enabling light emission (such as europium- or terbium-doped phosphors).

Activatoren are distinguished from inhibitors, which decrease activity. The exact meaning of the term is context-dependent, reflecting mechanisms from allosteric regulation and transcriptional control to catalytic acceleration and luminescent signaling.