For instance, neurotransmitters are a class of short-range signaling molecules that travel ... fall into three major classes: G-protein-coupled receptors, ion channel receptors, and enzyme-linked ...

An acetylcholine receptor (green) forms a gated ion channel in the plasma membrane. This receptor is a membrane protein with an aqueous pore ... When acetylcholine molecules (blue) bind to ...

From growth hormones to cancer drugs, small molecules play a ... the scientists fused the binding proteins to a newly ...