Orexin B, human TFA  (Synonyms: Human orexin B TFA)

Orexin B, human (TFA) is an endogenous agonist at Orexin receptor with K_is of 420 and 36 nM for OX1 and OX2, respectively.

Ki: 420 nM (OX1), 36 nM (OX2)^[1].

Orexin B is derived by proteolytic amino acid precursor, prepro-orexin, which is encoded by a gene localized to chromosome 17q21 in humans. In radioligand binding studies, Orexin B has a higher affinity for the OX2 receptor^[1].
Human Orexin B has two amino acid substitutions when compared with the rodent sequence. OX2 receptor is indeed a high-affinity receptor for human orexin B, with an IC₅₀ of 36 nM in the binding assay and an EC₅₀ of 60 nM in the [Ca²⁺]i transient assay. Human Orexin B has significantly lower affinity for the human OX1: the calculated IC₅₀ in the competitive binding assay and the EC₅₀ in the [Ca²⁺]i transient assay are 420 nM and 2500 nM for human orexin-B, respectively^[2].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Human Orexin B significantly augments food intake; at the 2 hr time point, 5- and 12-fold stimulation of food consumption is observed by 3 nM and 30 nM orexin-B, respectively^[2].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

3013.36

C₁₂₃H₂₁₂N₄₄O₃₅S.C₂HF₃O₂

Solid

White to off-white

Arg-Ser-Gly-Pro-Pro-Gly-Leu-Gln-Gly-Arg-Leu-Gln-Arg-Leu-Leu-Gln-Ala-Ser-Gly-Asn-His-Ala-Ala-Gly-Ile-Leu-Thr-Met-NH2

RSGPPGLQGRLQRLLQASGNHAAGILTM-NH2

Room temperature in continental US; may vary elsewhere.

Sealed storage, away from moisture

*In solvent : -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture)

* Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture). When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

* Note: If you choose water as the stock solution, please dilute it to the working solution, then filter and sterilize it with a 0.22 μm filter before use.

• [1]. Smart D, et al. Orexins: a new family of neuropeptides. Br J Anaesth. 1999 Nov;83(5):695-7.  [Content Brief]

  [2]. Sakurai T, et al. Orexins and orexin receptors: a family of hypothalamic neuropeptides and G protein-coupled receptors that regulate feeding behavior. Cell. 1998 Feb 20;92(4):573-85.  [Content Brief]