Description

Nori Human beta-Endophin ELISA Kit Summary

Alternative names for b-endophin: Beta-Endophin

Standard Curve

Kit Components
1. Pre-coated 96-well Microplate
2. Biotinylated Detection Antibody
3. Streptavidin-HRP Conjugate
4. Lyophilized Standards
5. TMB One-Step Substrate
6. Stop Solution
7. 20 x PBS
8. Assay Buffer

Other Materials Required but not Provided:
1. Microplate Reader capable of measuring absorption at 450 nm
2. Log-log graph paper or computer and software for ELISA data analysis
3. Precision pipettes (1-1000 µl)
4. Multi-channel pipettes (300 µl)
5. Distilled or deionized water

Protocol Outline
1. Prepare all reagents, samples and standards as instructed in the datasheet.
2. Add 100 µl of Standard or samples to each well and incubate 1 h at RT.
3. Add 100 µl of Working Detection Antibody to each well and incubate 1 h at RT.
4. Add 100 µl of Working Streptavidin-HRP to each well and incubate 20 min at RT.
5. Add 100 µl of Substrate to each well and incubate 5-30 min at RT.
6. Add 50 µl of Stop Solution to each well and read at 450 nm immediately.

Background:

β-Endorphin is an endogenous opioid neuropeptide and peptide hormone that is produced in certain neurons in the central and peripheral nervous systems. It is one of three endorphins that are produced in humans like α-endorphin and γ-endorphin.^[2] The amino acid sequence is: Tyr–Gly-Gly-Phe–Met–Thr–Ser–Glu–Lys-Ser-Gln-Thr-Pro–Leu–Val-Thr-Leu-Phe-Lys-Asn–Ala–Ile-Ile-Lys-Asn-Ala-Tyr-Lys-Lys-Gly-Glu (31 amino acids). The first 16 amino acids are identical to α-endorphin. Function of β-endorphin has been known to be associated with hunger, thrill, pain, maternal care, sexual behavior, and reward cognition. β-endorphin is primarily utilized in the body to reduce stress and maintain homeostasis. β-Endorphin is an agonist of the opioid receptors; it preferentially binds to the μ-opioid receptor and has the highest binding affinity to the receptor. Acytelation of the N-terminus of β-endorphin, however, inactivates the neuropeptide, preventing it from binding to its receptor. Localized function of β-endorphin results in release of β-endorphin in different brain regions such as the amygdala or the hypothalamus.^[1] The two main methods by which β-endorphin is utilized in the body are peripheral hormonal action^[2] and neuroregulation. β-endorphin and other enkephalins are often released with ACTH to modulate hormone system functioning. Neuroregulation by β-endorphin occurs through interference with the function of another neuropeptide, either by direct inhibition of neuropeptide release or induction of a signaling cascade that reduces a neuropeptide’s effects.^[3] β-endorphin modulates pain perception both in the central nervous system and the peripheral nervous system. T-lymphocytes release β-endorphin in this localized region, allowing it to bind to opioid receptors, causing direct inhibition of substance P.^[4] In the central nervous system, β-endorphin binds to opioid receptors in the dorsal root and inhibits the release of substance P in the spinal cord, reducing the number of excitatory pain signals sent to the brain.^[4] The hypothalamus responds to the pain signal by releasing β-endorphin through the periaqueductal grey network, which mainly acts to inhibit the release of GABA, a neurotransmitter which prevents the release of dopamine.^[6][13] Thus, the inhibition of GABA release by β-endorphin allows for a greater release of dopamine, in part contributing to the analgesic effect of β-endorphin.^[3] β-Endorphin has approximately 18 to 33 times the analgesic potency of morphine,^[16] though its hormonal effect is species dependent.^[2]

References

1. Veening JG, Barendregt HP (2015). Fluids and Barriers of the CNS. 12: 3.
2. Foley KM, et al. (1979). Proc National Academy Sci USA. 76 (10): 5377–81.
3. Dalayeun JF, Norès JM, Bergal S. Biomedicine & Pharmacotherapy. 47 (8): 311–20.
4. Luan YH, et al. (2017). Journal of Clinical Anesthesia. 37: 123–128.

Product Citation