Raman-laser and infrared Spectroscopy of biomolecules. Structural characterization of nucletides and proteins



With the purpose of characterizing by vibrational spectroscopy trimer of nucleic bases guanine-guanine-cytosine that exist in triplex helixes of nucleic acids, it has been obteined ready 18O(6)-guanosine for the first time by means of enzymatic synthesis starting from 6-chloro-guanosine in aqueous solution (H218O). The Raman and infrared spectra have been obtained in aqueous solution, under ionic conditions of the means to obtain guanosine gels associated by hydrogen bonds as the one denominated structure of Hoogsteen. To know the origin of the characteristic spectral profile of this structure type, the calculation of vibration frequencies has begun considering a possible electromagnetic dipolar coupling among carbonil groups located in bases of contiguous guanines.

On the other hand, we have been studied by Raman and infrared spectroscopy the interactions between DNA and the peptide (31-45) of the tumoral necrosis factor TNF-alpha, on one hand, and the interactions between gliceraldehyde-3-phosphatedeshidrogenase and the ribonucleic acid of transfer tRNAphe of the yeast, for another. The spectroscopyc studies carried out by means of isotopic exchange reveals changes up to now in the tertiary structure of both biomolecules types after the transformation of the respective intermolecular complexs.

This work has been supported, likewise, with a Special Action of the "Consejería de Educación y Cultura de la Comunidad de Madrid (AE 00415/95) titled " Structural study of complex between sour antitumoral nucleics and peptides."

Also, in collaboration with San Pablo-CEU University (Madrid), it has been carried out a Raman and infrared spectroscopyc study on topographical distribution of lipids in watery emulsions constituted by dipalmitoiphosphatidilcoline and oleate of cholesterol. It has been studied this system like simple model of lipidic emulsions of the lipoproteins of human plasm, using isotopic mark in the hydrocarbonated chains and carrying out spectra to variable temperature. The obtained results suggest the presence of particles constituted by an external phospholipidic monolayer in which are inserted, in some measure, hydrocarbonated chains of oleato of cholesterol, being located this inside the lipidic particles.

Likewise, thanks to the Prof. Juana Bellanato, the collaboration has been continued with the Departments of Animal Pathology, of the Faculty of Veterinary of the Complutense University of Madrid, and of Organic Chemistry, of the University of Alcala de Henares.


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