Cognitive · Neuropeptide
Orexin-B
Also known as Hypocretin-2
A 28-amino-acid neuropeptide, also known as Hypocretin-2, that activates both OX1 and OX2 receptors to regulate sleep-wake cycles.
- Length
- 28 amino acids
- Half-life
- Not well characterised
- Mechanism
- A linear hypothalamic neuropeptide that acts as a non-selective agonist for both the orexin receptor 1 (OX1R) and orexin receptor 2 (OX2R).
- Studied in
- Investigated in research models to differentiate the functions of OX1R and OX2R in sleep, metabolism, and stress responses.
About Orexin-B
Orexin-B, or Hypocretin-2, is a 28-amino-acid linear peptide processed from the same precursor, prepro-orexin, as Orexin-A. Unlike Orexin-A, it lacks disulfide bonds, resulting in a more flexible structure and lower stability in plasma. It is co-released with Orexin-A from neurons in the lateral hypothalamus.
This peptide serves as a non-selective agonist for both orexin receptors, OX1R and OX2R. Because Orexin-A has a preference for OX1R, Orexin-B is a useful tool for comparative studies aiming to elucidate the specific roles of OX2R. Research applications include the examination of sleep architecture, regulation of energy expenditure, and the modulation of the stress axis.
Laboratory notes
- Orexin-B is a linear peptide and lacks the disulfide bonds found in Orexin-A, making it less stable in biological fluids.
- Shows approximately equal affinity for both OX1 and OX2 receptors, in contrast to Orexin-A's preference for OX1.
- Its use in conjunction with Orexin-A or selective receptor antagonists allows for the functional dissection of the two orexin receptor pathways.
Storage and reconstitution basics: storage guide.
Questions about Orexin-B
What is Orexin-B?
Orexin-B, also called Hypocretin-2, is a neuropeptide involved in the central regulation of wakefulness and energy balance.
How is Orexin-B different from Orexin-A?
Orexin-B is a shorter, linear peptide with 28 amino acids and no disulfide bonds. It binds equally to both OX1 and OX2 receptors, while Orexin-A is a 33-amino-acid peptide with two disulfide bonds and a preference for the OX1 receptor.
Where is Orexin-B produced?
It is co-expressed and co-released with Orexin-A from neurons located in the lateral and posterior hypothalamus.
Is Orexin-B for human use?
No. It is supplied strictly for in-vitro laboratory research and is not for human or animal consumption.
Related research peptides
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