Dipeptide _L-Seryl-_L-Methionine—Linear Dichroic IR and Theoretical Characterization

ABSTRACT

The dipeptide _L -seryl- _L -methionine is elucidated structurally by means of solid-state linear dichroic infrared spectroscopy of oriented samples as a colloidal suspension in nematic liquid crystal as a part of our systematic study of OH-containing small peptides. Vibrational analysis supports the experimental data as well. Quantum chemical ab initio calculations are performed in order to obtain the electronic structure and vibrational characteristics of the system studied, where a cisoide-configuration of the C=O–NH amide fragment is predicted.

KEYWORDS:

• ab initio calculations
• linear dichroic infrared spectroscopy
• _L -seryl- _L -methionine
• solid-state

ACKNOWLEDGMENTS

The authors thank Prof. B. Koleva (Sofia University St. Kl. Ohridski) for helpful discussion and for the use of the Dalton 2.0 program package. We also wish to thank Prof. T. Kolev (Bulgarian Academy of Sciences) for the use of the Gaussian 98 program package.