TY - JOUR
T1 - Spare interactions of highly potent [Arg14,Lys15]nociceptin for cooperative induction of ORL1 receptor activation
AU - Isozaki, Kaname
AU - Li, Jinglan
AU - Okada, Kazushi
AU - Nishimura, Hirokazu
AU - Matsushima, Ayami
AU - Nose, Takeru
AU - Costa, Tommaso
AU - Shimohigashi, Yasuyuki
N1 - Funding Information:
This study was supported in part by Health and Labour Sciences Research Grants to Y.S. for Research on the Risk of Chemical Substances, from the Ministry of Health, Labor, and Welfare of Japan. This work was also supported in part by grants-in-aid from the Ministry of Education, Culture, Sports, Science, and Technology of Japan to Y.S.
PY - 2009/12/1
Y1 - 2009/12/1
N2 - [Arg14,Lys15]Nociceptin is a very potent for ORL1 receptor, showing a few times stronger binding activity and much more enhanced biological activity than endogenous nociceptin. This synergistic outcome has been suggested to be due to the interaction with the receptor aromatic and/or acidic amino acid residues crucial to receptor activation. In order to identify such receptor residues in the second ORL1 extracellular loop, we prepared a series of recombinant mutant receptors. The mutant receptor Gln205Ala was found to be as active as wild-type ORL1 for both nociceptin and [Arg14,Lys15]nociceptin. In contrast, Asp206Ala and Tyr207Ala exhibited considerably reduced activity for [Arg14,Lys15]nociceptin, exhibiting no synergistic activity enhancement. These results suggest that Asp206 and Tyr207 are directly involved in the interaction with nociceptin-[Arg14,Lys15]. Trp208Ala was found to bind strongly both nociceptin and [Arg14,Lys15]nociceptin, although it elicited no biological activity. All these results indicate that the consecutive amino acid residues Asp206, Tyr207, and Trp208 are critical to the activation of the ORL1 receptor, but not to nociceptin-binding.
AB - [Arg14,Lys15]Nociceptin is a very potent for ORL1 receptor, showing a few times stronger binding activity and much more enhanced biological activity than endogenous nociceptin. This synergistic outcome has been suggested to be due to the interaction with the receptor aromatic and/or acidic amino acid residues crucial to receptor activation. In order to identify such receptor residues in the second ORL1 extracellular loop, we prepared a series of recombinant mutant receptors. The mutant receptor Gln205Ala was found to be as active as wild-type ORL1 for both nociceptin and [Arg14,Lys15]nociceptin. In contrast, Asp206Ala and Tyr207Ala exhibited considerably reduced activity for [Arg14,Lys15]nociceptin, exhibiting no synergistic activity enhancement. These results suggest that Asp206 and Tyr207 are directly involved in the interaction with nociceptin-[Arg14,Lys15]. Trp208Ala was found to bind strongly both nociceptin and [Arg14,Lys15]nociceptin, although it elicited no biological activity. All these results indicate that the consecutive amino acid residues Asp206, Tyr207, and Trp208 are critical to the activation of the ORL1 receptor, but not to nociceptin-binding.
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U2 - 10.1016/j.bmc.2009.10.026
DO - 10.1016/j.bmc.2009.10.026
M3 - Article
C2 - 19879767
AN - SCOPUS:71849096217
SN - 0968-0896
VL - 17
SP - 7904
EP - 7908
JO - Bioorganic and Medicinal Chemistry
JF - Bioorganic and Medicinal Chemistry
IS - 23
ER -