obsolete kappa-opioid receptor activity true OBSOLETE. Combining with an opioid to initiate a change in cell activity, with the pharmacological characteristics of kappa-opioid receptors, including high affinity for dynorphins. Wikipedia:Kappa_Opioid_receptor This term was made obsolete because the receptor is defined based on its pharmacological properties. molecular_function kappa-opioid receptor activity GO:0004987 dynorphin receptor activity