ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The gel filtration method was applied to the study of the interaction of the metachromatic cationic dye methylene blue (MB) with heparin in aqueous solution. This method requires the determination of the total MB concentration in the effluent. It was found that (i) MB in aqueous solution can be extracted quantitatively with benzyl alcohol (BzlOH), (ii) the metachromatic effect of MB is not observed in BzlOH, and (iii) the presence of heparin in aqueous solution does not interfere in the BzlOH extraction of MB. Accurate determination of MB concentration in the effluent can be made by extraction of MB with BzlOH, followed by the usual absorption spectroscopy. In addition, the use of the spectrophotometric method with this procedure entailed no serious problem relating to adsorption of MB on the glass walls. Gel filtration binding experiments were successfully carried out on a Sephadex LH-20 column using 0.005M acetate buffer as effluent. The binding data obtained were analyzed in terms of the cooperativity parameter according to the method of Schwarz. The thermodynamic parameters for the binding process of MB were also evaluated. It is shown that the binding of MB to heparin is highly cooperative, exothermic, and stabilized by entropic factors.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.1981.360200603
