Identification of a key amino acid of the human 5-HT(2B) serotonin receptor important for sarpogrelate binding.
Based on radio-ligand binding and molecular modeling studies, sarpogrelate shows a moderate selectivity for 5-HT(2B) versus 5-HT(2A) receptors. To confirm the modeling data of sarpogrelate to 5-HT(2B) receptors predicting interaction of sarpogrelate towards Asp135 in helix 3 of 5-HT(2B) receptors, we constructed and characterized the mutation of this residue by site-directed mutagenesis. The Asp135Ala mutant did not exhibit any affinity for [(3)H]rauwolscine. Therefore, it was not possible to find sarpogrelate affinity to the mutant using [(3)H]rauwolscine. The mutation also abolished agonist-stimulated inositol phosphates formation. These results provide evidence that Asp135 is important for the interaction between 5-HT(2B) receptors and sarpogrelate.
Muntasir
Habib Abul
HA
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Niigata University of Pharmacy and Applied Life Sciences, 265-1 Higashijima, Akihaku, Niigata 956-8603, Japan.
Hossain
Murad
M
Bhuiyan
Mohiuddin Ahmed
MA
Komiyama
Tadazumi
T
Nakamura
Takashi
T
Ozaki
Masanobu
M
Nagatomo
Takafumi
T
D000596:Amino Acids / Q000378:metabolism*; D015153:Blotting, Western; D002460:Cell Line; D002478:Cells, Cultured; D003533:Cyproheptadine / Q000494:pharmacology; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D007295:Inositol Phosphates / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D011725:Pyridines / Q000494:pharmacology; D011869:Radioligand Assay; D044403:Receptor, Serotonin, 5-HT2B / Q000187:drug effects* / Q000235:genetics; D012702:Serotonin Antagonists / Q000378:metabolism*; D013386:Succinates / Q000378:metabolism*; D015016:Yohimbine / Q000378:metabolism
D000596:Amino Acids; D007211:Indoles; D007295:Inositol Phosphates; D011725:Pyridines; D044403:Receptor, Serotonin, 5-HT2B; D012702:Serotonin Antagonists; D013386:Succinates; C064294:sarpogrelate; D015016:Yohimbine; D003533:Cyproheptadine; C094868:SB 206553