Big dynorphin

 ( Neuropeptides ) 

Big dynorphin is an endogenous opioid peptide of the dynorphin family that is composed of both dynorphin A and dynorphin B. It is derived from the precursor protein prodynorphin, encoded by the PDYN gene. Big dynorphin is notable for its potent activity at opioid receptors and its role in modulating pain, stress, emotion, and neurophysiological functions such as learning and memory. Big dynorphin has the amino acid sequence: Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Ile-Arg-Pro-Lys-Leu-Lys-Trp-Asp-Asn-Gln-Lys-Arg-Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Gln-Phe-Lys-Val-Val-Thr. It has nociception and anxiolytic-like properties, as well as effects on memory in mice.

Big dynorphin is a principal endogenous, agonist at the human kappa-opioid receptor.

---

Receptor binding and activity Big dynorphin primarily acts as an agonist at κ-opioid receptors, where it exhibits high potency and efficacy, leading to analgesic, dysphoric, and sedative effects. Additionally, evidence suggests it may also interact with NMDA (N-methyl-D-aspartate) receptors independently of opioid pathways, contributing to effects on synaptic plasticity and neurotoxicity.

---

Physiological and behavioral effects Research has implicated big dynorphin in a variety of physiological processes:

• Pain modulation: Like other dynorphins, big dynorphin can produce analgesic effects but may also induce hyperalgesia in certain contexts.
• Emotion and stress: Big dynorphin is involved in the regulation of anxiety-like and depressive-like behaviors, often through its activation of the dynorphin/KOR system.
• Memory and learning: It has been shown to impair spatial memory in rodent models, possibly through NMDA receptor modulation.

---

Pathophysiological roles Big dynorphin levels are altered in several neuropsychiatric and neurodegenerative conditions:

• Depression and addiction: Alterations in dynorphin signaling, including big dynorphin, are linked to substance use disorders and stress-related mood disorders.

---

See also

• Dynorphin
• κ-Opioid receptor
• Prodynorphin
• Endogenous opioid peptides

Post Comment