We aim to probe the structural features of the G-protein coupled receptors (PTH1 and PTH2) for parathyroid hormone (PTH). PTH is one of the few bone-active agents proven to be anabolic in humans and therefore has been intensively examined as a possible target for the treatment of osteoporosis.
We aim to characterize, on a structural basis, the association of the receptor to the G-proteins (Gs and Gq) known to couple to it. Additionally, the association of PTH1 to beta-arrestin2, an important step in the internalization of the receptor will also be structurally examined.
A second aim i s to utilize the structural features of PTH and PTH1 previously determined in our group to rationally design low molecular weight PTH-based analogs. It is well established that the N-terminus of PTH is responsible for receptor activation. However, this domain alone, PTH(1-14), has extremely low binding affinity. Through random screening, analogs with low uM potencies (e.g., (Ala3, 10,12, Arg11)PTH(1-14)) have been developed. Our structural characterization of this lead compound has provided a number of methods to incorporate additional conformational constraint (cyclization) as well as non-natural amino acids and peptidomimetics. The research described here will facilitate the rational design and optimization of PTH-based agents for the regulation of calcium homeostasis.
A final aim i s to utilize the establishment of the pharmacophore for the PTH1 receptor, as well as structural characterization of TIP39 (tuberoinfundibular peptide-39) to develop a structure-activity relationship for the PTH2 receptor. Such information would facilitate the design of stable, PTH2 specific antagonist, which would assist in the establishing the physiological role of the receptor, thought to be involved in release of pituitary and pancreatic hormones and possibly perception of pain. Given that PTH activates both receptors, and TIP39(7-39) is specific for PTH1, there is a great synergy between the latter two aims; the results aimed to develop a valuable tool for the physiological characterization of PTH2 will accelerate the rational design of PTH1 receptor-specific, lead drug candidates for the treatment of osteoporosis.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
3R01GM054082-10S1
Application #
7256177
Study Section
Biophysical Chemistry Study Section (BBCB)
Program Officer
Chin, Jean
Project Start
1996-05-01
Project End
2007-03-31
Budget Start
2006-08-01
Budget End
2007-03-31
Support Year
10
Fiscal Year
2006
Total Cost
$88,913
Indirect Cost
Name
Brown University
Department
Pharmacology
Type
Schools of Medicine
DUNS #
001785542
City
Providence
State
RI
Country
United States
Zip Code
02912
Bucur, Octavian; Gaidos, Gabriel; Yatawara, Achani et al. (2015) A novel caspase 8 selective small molecule potentiates TRAIL-induced cell death. Sci Rep 5:9893
Pennarun, B; Gaidos, G; Bucur, O et al. (2013) killerFLIP: a novel lytic peptide specifically inducing cancer cell death. Cell Death Dis 4:e894
Yatawara, Achani; Wilson, Jamie L; Taylor, Linda et al. (2013) C-terminus of ETA/ETB receptors regulate endothelin-1 signal transmission. J Pept Sci 19:257-62
Audu, Christopher O; Cochran, Jared C; Pellegrini, Maria et al. (2013) Recombinant production of TEV cleaved human parathyroid hormone. J Pept Sci 19:504-10
Yatawara, Achani K; Hodoscek, Milan; Mierke, Dale F (2013) Ligand binding site identification by higher dimension molecular dynamics. J Chem Inf Model 53:674-80
Wang, Wenjing; Nossoni, Zahra; Berbasova, Tetyana et al. (2012) Tuning the electronic absorption of protein-embedded all-trans-retinal. Science 338:1340-3
Thomas, Beena E; Sharma, Sandhya; Mierke, Dale F et al. (2009) PTH and PTH antagonist induce different conformational changes in the PTHR1 receptor. J Bone Miner Res 24:925-34
Seck, Thomas; Pellegrini, Maria; Florea, Ana Maria et al. (2005) The delta e13 isoform of the calcitonin receptor forms a six-transmembrane domain receptor with dominant-negative effects on receptor surface expression and signaling. Mol Endocrinol 19:2132-44