β- Amyloid (1-33)

Dynorphin A (1-10) (TFA), an endogenous opioid neuropeptide, binds in the transmembrane domain of the κ-receptor.

β-Endorphin, an endogenous opioid neuropeptide, is an opioid receptor agonist. β-Endorphin binds preferentially to μ-opioid receptors and is produced in certain neurons of the central and peripheral nervous system and is one of three endorphins produced in humans. β-Endorphin can be used to reduce stress and maintain homeostasis in the body and is involved in neurological pain perception regulation.