| Autor: |
Olga, Bodet, Steffen, Goerke, Nicolas G R, Behl, Volkert, Roeloffs, Moritz, Zaiss, Peter, Bachert |
| Rok vydání: |
2014 |
| Předmět: |
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| Zdroj: |
NMR in biomedicine. 28(9) |
| ISSN: |
1099-1492 |
| Popis: |
Amide protons of peptide bonds induce an important chemical exchange saturation transfer (CEST) contrast in vivo. As a simple in vitro model for a peptide amide proton CEST effect, we suggest herein the dipeptide carnosine. We show that the metabolite carnosine creates a CEST effect and we study the properties of the exchange of the amide proton (-NH) of the carnosine peptide bond (NHCPB) in model solutions for a pH range from 6 to 8.3 and a temperature range from T = 5 °C to 43 °C by means of CEST and water exchange spectroscopy (WEX) experiments on a 3 T whole-body MR tomograph. The dependence of the NHCPB chemical exchange rate k(sw) on pH and temperature T was determined using WEX. For physiological conditions (T = 37 °C, pH = 7.10) we obtained k(sw) = (47.07 ± 7.90)/s. With similar chemical shift and exchange properties to amide protons in vivo, carnosine forms a simple model system for optimization of CEST pulse sequences in vitro. The potential for direct detection of the metabolite carnosine in vivo is discussed. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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