Human parathyroid hormone (hPTH) is an 84aa residue peptide and one of the main regulators in maintenance of calcium homeostasis. It acts primarily on kidney and bone cells stimulating calcium back resorption or calcium mobilization, respectively. The whole mechanism is still under discussion, but low-dose hPTH triggers cyclic AMP-dependent protein kinase in some populations of bone cells bearing PTH receptors, which stimulates the proliferation of osteoblasts. Source: Recombinant protein corresponding to aa32-115 from human PTH expressed in E. coli. Molecular Weight: ~9.55 kD (85aa), confirmed by MALDI-TOF Amino Acid Sequence: MSVSEIQLMH NLGKHLNSME RVEWLRKKLQ DVHNFVALGA PLAPRDAGSQ RPRKKEDNVL VESHEKSLGE ADKADVNVLT KAKSQ Endotoxin: ~1EU/1ug (LAL) Biological Activity: Measured by its ability to induce cAMP accumulation in MC3T3/E1 mouse preosteoblast cells. The ED50 for this effect is 50ng/ml. Storage and Stability: May be stored at 4C for short-term only. Aliquot to avoid repeated freezing and thawing.. Store at -20C. Aliquots are stable for 6 months after receipt at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
