Where does effector collide?

In biochemistry, an effector is a small molecule that binds a protein away from its active site and shifts the protein between conformations, so it tunes activity up or down without being the substrate. Monod, Wyman, and Changeux's 1965 On the nature of allosteric transitions: A plausible model formalised how such effectors stabilise one of two states of a multi-subunit enzyme and so regulate it. The referent is a regulatory ligand that modulates a protein's function allosterically, a different construct from an immune cell that carries out a response or a robot's working tip, sharing only the idea of a thing that brings about an effect.[1]

Unit

The change in protein activity produced by an effector's binding

Recovery means

Not applicable

Measured by

Characterised by binding and activity curves showing allosteric activation or inhibition

In immunology, an effector cell is a lymphocyte that has differentiated from a naive state into one that performs the immune response itself, such as a cytotoxic T cell that kills infected targets or a helper T cell that secretes cytokines, as opposed to the long-lived memory cells that persist afterward. Pipkin and Rao's 2009 SnapShot: Effector and memory T cell differentiation summarises how activated T cells branch into these effector and memory fates. The referent is the response-executing cell state, and it is distinct from a regulatory small molecule or a robot's end tool, joined only by the meaning of the part that does the work.[2]

Unit

The functional state of a lymphocyte carrying out the response

Recovery means

Not applicable

Measured by

Identified by surface markers, cytokine output, and cytotoxic or helper function