Biomaterial Database

Infrared dichroism of isotope-edited alpha-helices and beta-sheets. 2004

Derek Marsh

Max-Planck-Institut für biophysikalische Chemie, Abteilung Spektroskopie, 37070 Göttingen, Germany. dmarsh@gwdg.de

Isotope editing of amide infrared bands not only localises secondary structural elements within the protein but also yields conformational information that is not available from the linear dichroism of aligned samples without isotope editing. The additional information that can be derived on the orientational distribution of alpha-helices in membranes by the combined use of different amide bands and several positions of labelling is presented here. Also, the relationship between the azimuthal orientation of the transition moment and the protein structure is treated explicitly. A comprehensive analysis of the infrared dichroism for beta-sheets and beta-barrels is given here, for the first time. The orientation of the individual transition moments in a beta-sheet that is essential for this analysis is derived for the different amide bands.

UI	MeSH Term	Description	Entries
D007259	Infrared Rays	That portion of the electromagnetic spectrum usually sensed as heat. Infrared wavelengths are longer than those of visible light, extending into the microwave frequencies. They are used therapeutically as heat, and also to warm food in restaurants.	Heat Waves,Heat Wave,Infrared Ray,Ray, Infrared,Rays, Infrared,Wave, Heat,Waves, Heat
D007554	Isotopes	Atomic species differing in mass number but having the same atomic number. (Grant & Hackh's Chemical Dictionary, 5th ed)	Isotope
D008433	Mathematics	The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Mathematic
D008566	Membranes	Thin layers of tissue which cover parts of the body, separate adjacent cavities, or connect adjacent structures.	Membrane Tissue,Membrane,Membrane Tissues,Tissue, Membrane,Tissues, Membrane
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D000577	Amides	Organic compounds containing the -CO-NH2 radical. Amides are derived from acids by replacement of -OH by -NH2 or from ammonia by the replacement of H by an acyl group. (From Grant & Hackh's Chemical Dictionary, 5th ed)	Amide
D013057	Spectrum Analysis	The measurement of the amplitude of the components of a complex waveform throughout the frequency range of the waveform. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Spectroscopy,Analysis, Spectrum,Spectrometry
D017433	Protein Structure, Secondary	The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to ALPHA-HELICES; BETA-STRANDS (which align to form BETA-SHEETS), or other types of coils. This is the first folding level of protein conformation.	Secondary Protein Structure,Protein Structures, Secondary,Secondary Protein Structures,Structure, Secondary Protein,Structures, Secondary Protein