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A single position in the third transmembrane domains of the human B1 and B2 bradykinin receptors is adjacent to and discriminates between the C- terminal residues of subtype-selective ligands

Fathy, Dana B. ; Mathis, Sandra A. ; Leeb, Tosso and Leeb-Lundberg, L. M.F. LU (1998) In Journal of Biological Chemistry 273(20). p.12210-12218
Abstract

In order to identify agonist- and antagonist-binding epitopes in the human B1 and B2 bradykinin (BK) receptors, we exploited the ability of these receptors to discriminate between peptide ligands that differ only by the absence (B1) grid presence (B2) of a C-terminal Arg. This was done by constructing chimeric proteins in which specific domains were exchanged between these receptors as recently described by us (Leeb, T., Mathis, S. A, and Leeb-Lundberg, L. M. F. (1997) J. Biol. Chem. 272, 311-317). The constructs were then expressed in HEK293 and A10 cells and assayed by radioligand binding and by agonist-stimulated inositol phospholipid hydrolysis and intracellular Ca2+ mobilization. Substitution of the third transmembrane... (More)

In order to identify agonist- and antagonist-binding epitopes in the human B1 and B2 bradykinin (BK) receptors, we exploited the ability of these receptors to discriminate between peptide ligands that differ only by the absence (B1) grid presence (B2) of a C-terminal Arg. This was done by constructing chimeric proteins in which specific domains were exchanged between these receptors as recently described by us (Leeb, T., Mathis, S. A, and Leeb-Lundberg, L. M. F. (1997) J. Biol. Chem. 272, 311-317). The constructs were then expressed in HEK293 and A10 cells and assayed by radioligand binding and by agonist-stimulated inositol phospholipid hydrolysis and intracellular Ca2+ mobilization. Substitution of the third transmembrane domain (TM-III) of the B1 receptor in the B2 receptor (B2(B1III)) dramatically reduced the affinities of B2-selective peptide ligands including both the agonist BK and the antagonist NPC17731. High affinity binding of both ligands to B2(B1III) was fully regain when one residue, Lys111, in TM-III of this chimera was replaced with the corresponding wild-type (WT) B2 receptor residue, Ser (B2(B1IIIS111)). Replacement of Ser111 with Lys in the WT B2 receptor decreased the affinities of BK and NPC17731 and increased the affinity of the B1-selective des-Arg10 analog of NPC17731, NPC18565. The results show that the C- terminal residue of peptide agonists and antagonists when bound to the B2 receptor is adjacent to Ser111 in the receptor. A Lys at this position, as is the case in the WT B1 receptor, provides a positive charge that repels the C-terminal Arg in B2-selective peptides and attracts the negative charge of the C terminus of B1-selective peptides, which lack the C-terminal Arg. Therefore, the residues at this one single position are crucial in determining the peptide selectivity of B1 and B2 BK receptors.

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author
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Biological Chemistry
volume
273
issue
20
pages
12210 - 12218
publisher
ASBMB
external identifiers
  • pmid:9575169
  • scopus:0032524670
ISSN
0021-9258
DOI
10.1074/jbc.273.20.12210
language
English
LU publication?
no
id
6f25c306-ce5f-4262-8887-a2afb4231085
date added to LUP
2019-06-10 11:07:42
date last changed
2020-01-13 01:58:54
@article{6f25c306-ce5f-4262-8887-a2afb4231085,
  abstract     = {<p>In order to identify agonist- and antagonist-binding epitopes in the human B1 and B2 bradykinin (BK) receptors, we exploited the ability of these receptors to discriminate between peptide ligands that differ only by the absence (B1) grid presence (B2) of a C-terminal Arg. This was done by constructing chimeric proteins in which specific domains were exchanged between these receptors as recently described by us (Leeb, T., Mathis, S. A, and Leeb-Lundberg, L. M. F. (1997) J. Biol. Chem. 272, 311-317). The constructs were then expressed in HEK293 and A10 cells and assayed by radioligand binding and by agonist-stimulated inositol phospholipid hydrolysis and intracellular Ca<sup>2+</sup> mobilization. Substitution of the third transmembrane domain (TM-III) of the B1 receptor in the B2 receptor (B2(B1III)) dramatically reduced the affinities of B2-selective peptide ligands including both the agonist BK and the antagonist NPC17731. High affinity binding of both ligands to B2(B1III) was fully regain when one residue, Lys<sup>111</sup>, in TM-III of this chimera was replaced with the corresponding wild-type (WT) B2 receptor residue, Ser (B2(B1IIIS<sup>111</sup>)). Replacement of Ser<sup>111</sup> with Lys in the WT B2 receptor decreased the affinities of BK and NPC17731 and increased the affinity of the B1-selective des-Arg<sup>10</sup> analog of NPC17731, NPC18565. The results show that the C- terminal residue of peptide agonists and antagonists when bound to the B2 receptor is adjacent to Ser<sup>111</sup> in the receptor. A Lys at this position, as is the case in the WT B1 receptor, provides a positive charge that repels the C-terminal Arg in B2-selective peptides and attracts the negative charge of the C terminus of B1-selective peptides, which lack the C-terminal Arg. Therefore, the residues at this one single position are crucial in determining the peptide selectivity of B1 and B2 BK receptors.</p>},
  author       = {Fathy, Dana B. and Mathis, Sandra A. and Leeb, Tosso and Leeb-Lundberg, L. M.F.},
  issn         = {0021-9258},
  language     = {eng},
  month        = {05},
  number       = {20},
  pages        = {12210--12218},
  publisher    = {ASBMB},
  series       = {Journal of Biological Chemistry},
  title        = {A single position in the third transmembrane domains of the human B1 and B2 bradykinin receptors is adjacent to and discriminates between the C- terminal residues of subtype-selective ligands},
  url          = {http://dx.doi.org/10.1074/jbc.273.20.12210},
  doi          = {10.1074/jbc.273.20.12210},
  volume       = {273},
  year         = {1998},
}