TY - JOUR
T1 - Synthesis and characterization of novel biotinylated carboxyl-terminal parathyroid hormone peptides that specifically crosslink to the CPTH-receptor
AU - Banerjee, Santanu
AU - Selim, Hafez
AU - Suliman, Gihan
AU - Geller, Andrew I.
AU - Jüppner, Harald
AU - Bringhurst, F. Richard
AU - Divieti, Paola
N1 - Funding Information:
The authors would like to thank Dr. Henry M Kronenberg for his critical suggestions during the course of this study. This work was supported by the National Institute of Health Grants DK-02889 and DK-65032 to P.D. and AR 47062 to F.R.B. and by an educational grant from NPS Pharmaceuticals.
PY - 2006/12
Y1 - 2006/12
N2 - Parathyroid hormone (PTH) regulates calcium, phosphorous and skeletal homeostasis via interaction with the G protein-coupled PTH/PTHrP receptor, which is fully activated by the amino-terminal 34 amino-acid portion of the hormone. Recent evidence points to the existence of another class of receptors for PTH that recognize the carboxyl (C)-terminal region of intact PTH (1-84) (CPTHRs) and are highly expressed by osteocytes. Here we report the synthesis and characterization of two novel bifunctional CPTH ligands that include benzoylphenylalanine (Bpa) substitutions near their amino-termini and carboxyl-terminal biotin moieties, as well as a tyrosine34 substitution to enable radioiodination. These peptides are shown to bind to CPTHRs with affinity similar to that of PTH (1-84) and to be specifically and covalently crosslinked to CPTHRs upon exposure to ultraviolet light. Crosslinking to osteocytes or osteoblastic cells generates complexes of 80 and 220 kDa, of which the larger form represents an aggregate that can be resolved into the 80 kDa. The crosslinked products can be further purified using immunoaffinity and avidin-based affinity procedures. While the molecular structure of the CPTHR(s) remains undefined, these bifunctional ligands represent powerful new tools for use in isolating and characterizing CPTHR protein(s).
AB - Parathyroid hormone (PTH) regulates calcium, phosphorous and skeletal homeostasis via interaction with the G protein-coupled PTH/PTHrP receptor, which is fully activated by the amino-terminal 34 amino-acid portion of the hormone. Recent evidence points to the existence of another class of receptors for PTH that recognize the carboxyl (C)-terminal region of intact PTH (1-84) (CPTHRs) and are highly expressed by osteocytes. Here we report the synthesis and characterization of two novel bifunctional CPTH ligands that include benzoylphenylalanine (Bpa) substitutions near their amino-termini and carboxyl-terminal biotin moieties, as well as a tyrosine34 substitution to enable radioiodination. These peptides are shown to bind to CPTHRs with affinity similar to that of PTH (1-84) and to be specifically and covalently crosslinked to CPTHRs upon exposure to ultraviolet light. Crosslinking to osteocytes or osteoblastic cells generates complexes of 80 and 220 kDa, of which the larger form represents an aggregate that can be resolved into the 80 kDa. The crosslinked products can be further purified using immunoaffinity and avidin-based affinity procedures. While the molecular structure of the CPTHR(s) remains undefined, these bifunctional ligands represent powerful new tools for use in isolating and characterizing CPTHR protein(s).
KW - Benzoylphenylalanine
KW - Carboxy-terminal parathyroid hormone
KW - Parathyroid hormone
KW - Parathyroid hormone receptor type-1
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U2 - 10.1016/j.peptides.2006.08.022
DO - 10.1016/j.peptides.2006.08.022
M3 - Article
C2 - 17028061
AN - SCOPUS:33750946940
VL - 27
SP - 3352
EP - 3362
JO - Peptides
JF - Peptides
SN - 0196-9781
IS - 12
ER -