dynorphin b

**Dynorphin B** is an endogenous opioid peptide derived from the precursor protein prodynorphin via cleavage by proprotein convertase 2. It is one of three major dynorphin peptides (alongside dynorphin A and neoendorphin) found in the central nervous system, particularly in regions such as the hypothalamus, medulla, pons, midbrain, and spinal cord[4][5]. Dynorphin B has the highest affinity for the **kappa opioid receptor (KOR)**, where it acts primarily as an agonist, eliciting inhibitory effects on neurotransmission and analgesia, but is also known to bind with lower affinity to mu and delta opioid receptors[1][5]. It can also exert effects via non-opioid pathways, including activation of protein kinase D (PKD) and dynamin-related protein 1 (DRP1), leading to mitochondrial fragmentation and dysfunction in certain cell types and mediating gene transcription in cell nuclei, particularly for cardiac lineage-associated genes (GATA-4 and Nkx-2.5)[2][3]. Its actions influence mood disorders, addiction behaviors, analgesia, dysphoria, stress responses, and mitochondrial dynamics.

Other names

dynorphin Bdyn B