Hormone · N-terminally truncated parathyroid hormone fragment; pathway-dependent PTH receptor ligand
Parathyroid hormone (3-34)
Also known as PTH(3-34)
A 32-residue PTH fragment for examining how removal of the first two residues changes receptor activation and pathway coupling.
- Length
- 32 amino acids
- Half-life
- Not well characterised
- Mechanism
- Removal of PTH residues 1 and 2 alters activation of PTH1R while preserving substantial receptor-binding capacity. PTH(3-34) can display antagonism or residual agonism depending on the signalling endpoint, receptor expression and peptide chemistry.
- Studied in
- Recombinant PTH1R systems, renal preparations and osteoblast-lineage cells are used to compare receptor binding with cAMP, phosphoinositide and other signalling readouts.
About Parathyroid hormone (3-34)
Parathyroid hormone (3-34) comprises residues 3 through 34 of PTH and therefore contains 32 amino acids. It retains nearly all of the commonly studied PTH(1-34) region while removing the first two N-terminal residues. This relatively small truncation has made it useful in structure–activity studies of receptor activation. As with other PTH fragments, species origin and terminal modifications must be specified before comparing results across preparations or published experiments reliably.
PTH1R recognises both PTH and PTH-related protein, but receptor binding does not guarantee equal activation of every downstream pathway. PTH(3-34) illustrates this distinction: loss of the first two residues can markedly reduce canonical cAMP signalling while leaving other responses detectable in particular systems. Some studies report phosphoinositide-related activity, although its magnitude depends on the experimental preparation. Describing the fragment simply as a universal antagonist or a uniformly pathway-selective agonist would overstate the evidence.
Laboratory notes
- Check the certificate of analysis for sequence origin and C-terminal chemistry before matching the material to a published assay.
- Run cAMP and phosphoinositide or calcium assays independently rather than inferring one pathway's activity from another.
- Document receptor expression and assay timing, because receptor reserve and signal amplification can reveal otherwise weak partial agonism.
Storage and reconstitution basics: storage guide.
Questions about Parathyroid hormone (3-34)
Is PTH(3-34) a pure antagonist?
Not universally. Its behaviour can include antagonism or residual agonism, depending on the receptor system and the endpoint measured.
How does PTH(3-34) differ from PTH(7-34)?
PTH(3-34) retains residues 3 through 6, which are absent from PTH(7-34). These additional N-terminal residues can change receptor activation and signalling efficacy.
Which experiments best characterise its signalling profile?
Combine binding measurements with fragment-alone concentration–response assays and agonist-competition experiments across separately measured signalling pathways.
Is Parathyroid hormone (3-34) 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.