Modern spectroscopy on biological molecules : structure and bonding investigated by THz time-domain and transient phase-grating spectroscopy

Since the first freely propagating THz pulses have been used to conduct spectroscopic investigations in the far-IR, THz time-domain spectroscopy (THz-TDS) has evolved into a versatile tool for the study of a variety of different sample materials. However its application to the investigation of biological molecules in this highly interesting spectral regime started only <br>recently, and the work presented in this thesis represents one of the first investigations along this line. <br> <br>We present characteristic THz spectra of individual biomolecular systems in the crystalline and amorphous phase. In particular the correlation between the observed low-frequency modes and molecular structure and association was investigated. Our results show that the mode structure in the THz region represents a unique fingerprint for the molecular structure and conformation, e.g. allowing to distinguish related compounds, to discriminate between <br>different isomers and to even observe structural phase-transitions. Potential applications in chemical recognition and drug screening are feasible. <br> <br>As a complementary approach we introduce a Transient phase-grating (TPG) spectroscopy as a novel spectroscopic technique capable of measuring volume changes of biomolecules. Its unique sensitivity to changes in the molecules' structure combined with a potential time-resolution from the femto- to the milli-second range make it a powerful technique capable of giving a complete history of relevant motions in proteins. <br> <br>Both techniques have now evolved to invaluable tools in modern spectroscopy. Their application to the investigation of biomolecules will significantly contribute to the solution of diverse problems in biological research.

Author dc:creator

• Walther, Markus

Contributors dc:contributor

• Helm, Hanspeter

• Terahertz-timedomain-spectroscopy
• Biomoleküle
• Strukturuntersuchung
• biomolecules
• structure determination

Repository record source_url

https://freidok.uni-freiburg.de/data/1168

OAI identifier oai:identifier

oai:freidok.uni-freiburg.de:1168