$121.00 - $121.00
[Ala11,D-Leu15]-Orexin B is a 28-residue engineered Orexin B analog developed as a highly selective OX2 receptor agonist. Two targeted substitutions—Ala11 and D-Leu15—reduce OX1 receptor activity while retaining strong OX2R activation.
Product Information
| Property | Specification |
|---|---|
| Sequence | Arg-Ser-Gly-Pro-Pro-Gly-Leu-Gln-Gly-Arg-Ala-Gln-Arg-Leu-D-Leu-Gln-Ala-Ser-Gly-Asn-His-Ala-Ala-Gly-Ile-Leu-Thr-Met-NH₂ |
| Peptide Length | 28 amino-acid residues |
| Molecular Formula | C120H206N44O35S |
| Molecular Weight | Approximately 2857.3 Da |
| CAS No. | 532932-99-3 |
| Key Modifications | Leu11 → Ala; Leu15 → D-Leu |
| Research Target | OX2 receptor |
Two Substitutions Create Strong OX2 Selectivity
Systematic Orexin B substitution studies identified residues within the central helical region as important determinants of receptor subtype recognition.
Combining Ala11 with D-Leu15 produced a peptide that maintained high OX2R activity while substantially weakening OX1R activation.
Reported Functional Selectivity
The original study reported EC50 values of approximately 0.13 nM at OX2R and 52 nM at OX1R, corresponding to roughly 400-fold functional selectivity under the tested conditions.
We recommend treating these values as assay-specific reference measurements rather than fixed lot specifications.
A Tool for Receptor-Subtype Assignment
This analog can help distinguish OX2-mediated responses from those produced by nonselective Orexin A or less-selective Orexin B. Receptor-selective antagonists or genetic controls remain useful when definitive pathway assignment is required.
Frequently Asked Questions
Is this an OX2 antagonist?
No. It is an OX2-selective agonist.
Why is D-Leu15 important?
The D-stereochemical substitution helps change receptor-subtype recognition while retaining strong OX2R activation.