For #neuropeptide afficionados:
Interesting new paper from James Checco's lab on two #Aplysia #allatotropin / #orexin receptors, one activated by a D-peptide the other one by an L-peptide.
Conversion of an L-stereoisomer to a D-stereoisomer is a big mystery in peptide biology - but it matters for rec specificity and lifetime.
https://www.pnas.org/doi/10.1073/pnas.2217604120