Regenerative · C-terminal PTHrP-derived pentapeptide
Osteostatin
Also known as PTHrP(107–111); TRSAW
The PTHrP-derived pentapeptide TRSAW, studied for non-canonical signalling in bone-cell and biomaterial research.
- Length
- 5 amino acids
- Half-life
- Not well characterised
- Mechanism
- Osteostatin has cell-modulatory activity in skeletal research models that is distinct from the canonical N-terminal PTHrP–PTH1R interaction. A definitive cognate receptor has not been established; reported signalling responses are model-dependent.
- Studied in
- Osteostatin is investigated in osteoclast resorption assays, osteoblast-lineage cultures and biomaterial-associated animal skeletal models.
About Osteostatin
Osteostatin is the pentapeptide Thr–Arg–Ser–Ala–Trp, corresponding to residues 107–111 of mature parathyroid hormone-related protein. It emerged from research mapping skeletal activities within the C-terminal portion of PTHrP, separate from the N-terminal region that activates PTH1R. Early experimental work associated this short sequence with reduced osteoclast-mediated resorption in laboratory systems. Its small size makes it useful for examining whether a discrete motif accounts for activities reported with larger C-terminal PTHrP fragments in matched experimental settings.
Subsequent studies have examined osteostatin in osteoblast-lineage cultures and peptide-bearing materials, using cellular differentiation, matrix-associated markers and signalling measurements as endpoints. Its mechanism remains less clearly resolved than that of N-terminal PTHrP fragments, and the name does not imply a validated receptor target. Responses can vary with cell maturation state, experimental context and material presentation. Direct comparisons with PTHrP(107–139), together with sequence controls, help distinguish the pentapeptide's contribution from effects requiring a longer molecular context.
Laboratory notes
- Confirm the TRSAW sequence and terminal chemistry, especially when comparing the isolated peptide with a longer PTHrP fragment.
- Monitor integrity where oxidation is a concern, as the tryptophan residue can undergo oxidative modification.
- Pair resorption or differentiation endpoints with cell-number and viability measurements to identify non-specific changes.
Storage and reconstitution basics: storage guide.
Questions about Osteostatin
Is osteostatin the same as PTHrP(107–139)?
No. Osteostatin comprises residues 107–111, whereas PTHrP(107–139) is a 33-residue fragment containing that motif at its N-terminus.
Is PTH1R its established receptor?
No. Osteostatin lacks the N-terminal PTHrP receptor-activating domain, and a definitive cognate receptor has not been established.
Which sequence should be listed for osteostatin?
The standard pentapeptide sequence is TRSAW. Any terminal modification or conjugation should be specified separately.
Is Osteostatin for human use?
No. It is supplied strictly for in-vitro laboratory research and is not for human or animal consumption.
Related research peptides
All products are sold for laboratory research use only. Not for human consumption, not a medicine, not for diagnosing, treating or preventing any condition.