The neurokinin-1 and neurokinin-2 receptor binding sites of MDL103,392 differ

详细信息    查看全文

• 作者：Greenfeder ; Scott ; Cheewatrakoolpong ; Boonlert ; Billah ; Motasim ; Egan ; Robert W. ; Keene ; Elizabeth ; et. al.
• 关键词：Antagonists ; mutagenesis ; tachykinins ; receptors
• 刊名：Bioorganic and Medicinal Chemistry
• 出版年：1999
• 出版时间：December, 1999
• 年：1999
• 卷：7
• 期：12
• 页码：2867-2876
• 全文大小：394 K

文摘

Several small molecule non-peptide antagonists of the NK-1 and NK-2 receptors have been developed. Mutational analysis of the receptor protein sequence has led to the conclusion that the binding site for these non-peptide antagonists lies within the bundle created by transmembrane domains IV–VII of the receptor and differs from the binding sites of peptide agonists and antagonists. The current investigation uses site-directed mutagenesis of the NK-1 and NK-2 receptors to elucidate the amino acids that are important for binding and functional activity of the first potent dual NK-1/NK-2 antagonist MDL103,392. The amino acids found to be important for MDL103,392 binding to the NK-1 receptor are Gln-165, His-197, Leu-203, Ile-204, Phe-264, His-265 and Tyr-272. The amino acids found to be important for MDL103,392 binding to the NK-2 receptor are Gln-166, His-198, Tyr-266 and Tyr-289. While residues in transmembrane (TM) domains IV and V are important in both receptors (Gln-165/166 and His-197/198), residues in TM V and VI are more important for the NK-1 receptor and residues in TM VII play a more important role in the NK-2 receptor. These data are the first report of the analysis of the binding site of a dual tachykinin receptor antagonist and indicate that a single compound (MDL103,392) binds to each receptor in a different manner despite there being a high degree of homology in the transmembrane bundles. In addition, this is the first report in which a model for the binding of a non-peptide antagonist to the NK-2 receptor is proposed.