Interaction of cationic cyanine dye with algal alginates: evidence for a polymer bound dye dimer
Sa’ib J. Khouri, Volker Buss
DOI: 10.4236/jbpc.2011.24043   PDF   HTML   XML   4,708 Downloads   9,043 Views   Citations


Under certain conditions algal alginates bind pinacyanol chloride in the form of dimers – this is the conclusion drawn from a uv/vis and circular dichroism (CD) spectroscopic study of aqueous solutions of the dye in a 10-fold molar excess of the polysaccharide from different sources. With its easily detected features the dimer holds promise as a diagnostic tool for alginate conformational analysis. Binding of the strongly blue-shifted (maximum wavelength = 485 nm) dimer is probably mediated by the charged groups and involves guluronate units only. By using the peakFit program, the two overlapping excitonic absorption bands together with the optically inactive band resulted from the interaction of pinacyanol with a specific alginate concentration were separated. The standard Gibbs energy of the interaction was calculated as –27.02 kJ.mol–1. The dimers are sensitive against acid and divalent cations.

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Khouri, S. and Buss, V. (2011) Interaction of cationic cyanine dye with algal alginates: evidence for a polymer bound dye dimer. Journal of Biophysical Chemistry, 2, 380-385. doi: 10.4236/jbpc.2011.24043.

Conflicts of Interest

The authors declare no conflicts of interest.


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