ENK - Enkephalin | Elisa - Clia - Antibody - Protein

Background:

Enkephalins are a type of endogenous opioid peptide neurotransmitter that are composed of five amino acids. They are found naturally in the human body and are part of the endorphin family. Enkephalins exert their effects by binding to opioid receptors in the brain and peripheral tissues, modulating pain perception, mood, and other physiological processes. Enkephalins are short peptides composed of five amino acids. The two primary forms of enkephalins are Met-enkephalin and Leu-enkephalin, which differ in their amino acid sequence at the third position (methionine for Met-enkephalin and leucine for Leu-enkephalin). These peptides are derived from larger precursor proteins called proenkephalins. Enkephalins act as endogenous analgesics, meaning they help modulate pain perception. They achieve this by binding to opioid receptors in the brain and spinal cord, particularly the mu opioid receptors, which are involved in mediating the analgesic effects of opioids. Enkephalins, along with other endorphins, can also influence mood and emotions. They are involved in the brain's reward pathways and may contribute to feelings of pleasure and well-being.

Protein Structure:

Enkephalins are pentapeptides, consisting of five amino acids. There are two primary forms:

• Met-enkephalin: Tyr-Gly-Gly-Phe-Met
• Leu-enkephalin: Tyr-Gly-Gly-Phe-Leu

Both peptides share the same four amino acids at the N-terminus but differ at the C-terminal position.

Classification and Subtypes:

Enkephalins belong to the class of opioid peptides and are classified based on their amino acid sequence:

• Met-enkephalin
• Leu-enkephalin

These peptides are derived from the precursor protein proenkephalin A, which is processed by proteolytic enzymes to release the active enkephalins.

Function and Biological Significance:

• Pain Modulation: Enkephalins bind to delta (δ) and mu (μ) opioid receptors in the brain and spinal cord, inhibiting the release of neurotransmitters involved in pain transmission and reducing the perception of pain.
• Stress Response: Enkephalins are involved in the body's response to stress, providing analgesic effects during stressful situations.
• Immune Function: Enkephalins influence the immune system by modulating the activity of immune cells, such as natural killer cells and macrophages.
• Neurotransmission: They modulate neurotransmitter release, affecting various physiological processes, including mood, behavior, and autonomic functions.

Interactions:

• Opioid Receptors: Enkephalins primarily interact with delta (δ) and mu (μ) opioid receptors. Binding to these receptors triggers a cascade of intracellular events, including inhibition of adenylate cyclase, decreased cAMP levels, and reduced calcium ion influx, leading to decreased neurotransmitter release.
• Enzymes: Enkephalins are rapidly degraded by peptidases such as enkephalinases, which limit their duration of action in the synaptic cleft.

Clinical Issues:

• Pain Management: Enkephalins have potential therapeutic applications in pain management, particularly in developing treatments that can provide analgesia without the addictive properties of synthetic opioids.
• Opioid Addiction: Understanding the role of enkephalins and their receptors can help in designing strategies to treat opioid addiction by modulating the endogenous opioid system.
• Mood Disorders: Dysregulation of enkephalin levels and opioid receptor function has been implicated in mood disorders such as depression and anxiety, suggesting that enkephalins could be targets for novel antidepressant therapies.

Summary:

Enkephalins are endogenous opioid peptides that play a crucial role in modulating pain, stress responses, and various physiological functions. Met-enkephalin and Leu-enkephalin are the primary forms, derived from proenkephalin A and act mainly through delta and mu opioid receptors. These interactions result in analgesic and mood-altering effects. Enkephalins' involvement in pain modulation and their potential therapeutic applications in pain management, opioid addiction, and mood disorders highlight their significant biological and clinical relevance.