Here’s something interesting: our main sweet taste receptor is a heterodimer, meaning two receptors have products that work together to detect the ‘sweet’ taste sensation (TAS1R and TAS3R). When working as a homodimer, TAS3R is less sensitive to sweet and this may explain why artificial sweeteners ‘taste’ different (this gets most interesting when the sense of smell is lost b/c the sense of smell is what makes chocolate sweet different from vanilla sweet).
I assume that the run for the money in the taste industry is for getting an artificial sugar ligand that binds to the heterodimer complex!.
The Smell of Evolution 