Thermally induced hydrogen exchange processes in small proteins as seen by FTIR spectroscopy

✍ Scribed by Backmann, Jan; Schultz, Christian; Fabian, Heinz; Hahn, Ulrich; Saenger, Wolfram; Naumann, Dieter

• Book ID: 102648372
• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 899 KB
• Volume: 24
• Category: Article
• ISSN: 0887-3585
• DOI: 10.1002/(sici)1097-0134(199603)24:3<379::aid-prot11>3.0.co;2-j

✦ Synopsis

Fourier-transform infrared (FTIR) spectroscopy has been used to study the thermally induced exchange characteristics of those backbone amide protons which persist H-D exchange at ambient conditions in ribonuclease A, in wild type ribonuclease TI and some of its variants, and in the histone-like protein HBsu. The H-D exchange processes were induced by increasing the thermal energy of the protein solutions in two ways: (i) by linearly increasing the temperature, and (ii) by a temperature jump. To trace the H-D exchange in the proteins, various infrared absorption bands known to be sensitive to H-D exchange were used as specific monitors. Characteristic H-D exchange curves were obtained from which the endpoints (THm) of H-D exchange could be determined. The H-D exchange curves, the T,,,values and the phase transition temperatures T, were used to estimate the structural flexibility and stability of the given proteins. It is suggested that time-resolved FTIR spectroscopy can be used to determine global stability parameters of proteins.