The relevance of imidazole tautomerism for the hormonal activity of histidine-containing peptides |
| |
| Authors: | Ernest Giralt Maria-Dolors Ludevid Enrique Pedroso |
| |
| Affiliation: | 1. Department de Química Orgànica, Facultat de Química, Universitat de Barcelona, 08028 Barcelona, Spain;2. Instituto de Biología de Barcelona CSIC, 08028 Barcelona, Spain;1. Organic and Bioorganic Chemistry, Faculty of Chemistry, Bielefeld University, D-33501 Bielefeld, Germany;2. Chemistry Department, Faculty of Science, Al-Azhar University, Nasr City-Cairo 11884, Egypt;3. Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm D-89081, Germany;4. Department of Pharmacognosy, College of Pharmacy, Cairo University, Cairo 11562, Egypt;5. Chemistry of Natural Compounds Department, Pharmaceutical and Drug Industries Research Division, National Research Centre, El-Buhouth St. 33, Dokki-Cairo 12622, Egypt;1. School of Chemical Sciences, Dublin City University, Dublin 9, Ireland;2. National Institute for Cellular Biotechnology, Dublin City University, Dublin 9, Ireland;3. Dept. of Medical Oncology, St. Vincent''s University Hospital, Dublin 4, Ireland;4. Dept. of Food Biosciences, Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland;1. Department of Chemistry, California State University, Fresno, 2555 E. San Ramon Avenue, M/S SB70, Fresno, CA 93740, USA;2. Department of Chemistry, Xavier University of Louisiana, 1 Drexel Drive, New Orleans, LA 70125, USA;3. RCMI Cancer Research Center, Xavier University of Louisiana, 1 Drexel Drive, New Orleans, LA 70125, USA;1. Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, FL, 32610, USA;2. Department of Medicinal Chemistry, School of Pharmacy, The University of Mississippi, University, Mississippi, 38677, USA;3. Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, WV, 26506, USA;4. College of Pharmacy, Touro University California, Vallejo, CA, 94592, USA |
| |
| Abstract: | Substitution of 5-nitro--histidine for -histidine is proposed as a useful tool to study the relationships among tautomerism, acid-base properties, and biological activity of peptide hormones. This approach is illustrated by an analog of the tripeptide thyroliberin, [5-nitro--histidine]2-thyroliberin, which has been prepared by solid-phase peptide synthesis. The acid-base properties of the hormone analog and the position of the imidazole ring tautomeric equilibrium have been investigated by spectroscopic methods. Correlation of these properties with the biological activity of the nitrated tripeptide strongly supports the idea that imidazole ring tautomerism is a key factor for hormonal activity and that the Nτ-H tautomer must be considered the biologically active form of thyroliberin. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
