Circular dichroism spectroscopic study of non-covalent interactions of poly-L-glutamic acid with a porphyrin derivative in aqueous solutions
✍ Scribed by Lukáš Palivec; Marie Urbanová; Karel Volka
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 221 KB
- Volume
- 11
- Category
- Article
- ISSN
- 1075-2617
- DOI
- 10.1002/psc.672
No coin nor oath required. For personal study only.
✦ Synopsis
The interactions of poly-L-glutamic acid and a cationic porphyrin derivative in aqueous solutions were studied by the combination of vibrational circular dichroism (VCD) and electronic circular dichroism (ECD) spectroscopies. It was found that non-covalent interactions between both agents influence the structure of the polymeric matrix and the guest porphyrins and vice versa, but the physico-chemical properties of the solutions, especially the pH and the relative permittivity of the solvent, play a key role in the structure of the polypeptide part of the formed complexes. It was shown that the interaction with porphyrins prevents the precipitation of poly-L-glutamic acid in aqueous solution at acidic pH. In special conditions, the porphyrins attached to the polypeptide probably possess face-to-face interaction as demonstrated by the enhancement of the characteristic ECD signal and the appearance of sidebands on its short and long wavelength sides.