TY - JOUR
T1 - Reciprocal mutations in TM2/TM3 in a D2 dopamine receptor background confirms the importance of this microdomain as a selective determinant of Para-halogenated 1,4-disubstituted aromatic piperazines
AU - Floresca, Christina Z.
AU - Chen, Shiuhwei
AU - Kortagere, Sandhya
AU - Schetz, John A.
PY - 2005/6
Y1 - 2005/6
N2 - We recently demonstrated that in the D4 dopamine receptor the aromatic microdomain that spans the interface of the second and third transmembrane (TM) domains influences the high affinity interactions of extremely D4-selective ligands possessing a 1,4-disubstituted aromatic piperazine/piperidine (1,4-DAP) structure. On the basis of their substructural features and patterns of sensitivity to mutations constructed in a D4 receptor background, the D4-selective 1,4-DAPs were categorized as having two distinct modes of binding that we named mode-1 and mode-3 [1]. Here we extend these findings of the ligand-receptor structure-affinity relationships for some of these highly D4-selective 1,4-DAPs by measuring the effect of the corresponding reciprocal TM2/TM3 mutations constructed in a D2 dopamine receptor background on the binding affinity of the para-halogenated mode-1 ligands L750,667 and FAUC213. The results indicate that the D2-V2.61F+FV3.28-3.29LM mutant binds L750,667 and FAUC213 with significantly increased affinity, i.e., its binding profile becomes more D4-like. These findings further support the assignment of the TM2/TM3 aromatic microdomain encompassing positions 2.61 and 3.28-3.29 as a 1,4-DAP D4-selectivity microdomain and highlights the importance of the precise emplacement of aromatics in this microdomain as key to the selective molecular recognition of L750,667 and FAUC213.
AB - We recently demonstrated that in the D4 dopamine receptor the aromatic microdomain that spans the interface of the second and third transmembrane (TM) domains influences the high affinity interactions of extremely D4-selective ligands possessing a 1,4-disubstituted aromatic piperazine/piperidine (1,4-DAP) structure. On the basis of their substructural features and patterns of sensitivity to mutations constructed in a D4 receptor background, the D4-selective 1,4-DAPs were categorized as having two distinct modes of binding that we named mode-1 and mode-3 [1]. Here we extend these findings of the ligand-receptor structure-affinity relationships for some of these highly D4-selective 1,4-DAPs by measuring the effect of the corresponding reciprocal TM2/TM3 mutations constructed in a D2 dopamine receptor background on the binding affinity of the para-halogenated mode-1 ligands L750,667 and FAUC213. The results indicate that the D2-V2.61F+FV3.28-3.29LM mutant binds L750,667 and FAUC213 with significantly increased affinity, i.e., its binding profile becomes more D4-like. These findings further support the assignment of the TM2/TM3 aromatic microdomain encompassing positions 2.61 and 3.28-3.29 as a 1,4-DAP D4-selectivity microdomain and highlights the importance of the precise emplacement of aromatics in this microdomain as key to the selective molecular recognition of L750,667 and FAUC213.
KW - Biogenic amine
KW - G protein-coupled receptor (GPCR)
KW - Molecular recognition
KW - Reciprocal mutations
KW - Subtype-selective
UR - http://www.scopus.com/inward/record.url?scp=21844453671&partnerID=8YFLogxK
U2 - 10.1002/ardp.200400993
DO - 10.1002/ardp.200400993
M3 - Article
C2 - 15952239
AN - SCOPUS:21844453671
SN - 0365-6233
VL - 338
SP - 268
EP - 275
JO - Archiv der Pharmazie
JF - Archiv der Pharmazie
IS - 5-6
ER -