ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The interactions between chondroitin-6-sulfate and poly-L-arginine in aqueous salt solution have been investigated by circular dichroism techniques. In the presence of chondroitin-6-sulfate, at neutral pH, poly-L-arginine adopts the α-helical conformation rather than “charged coil” form observed in the absence of mucopolysaccharide. This interaction is at a maximum when the ratio of arginine to disaccharide residues is 2:1. Elevation of the temperature leads to a sharp melting transition at 76.0 ± 1.0°C. This behavior is in marked contrast to that for poly-L-lysine-chondroitin-6-sulfate interactions, which are at a maximum at a 1:1 residue ratio and have a melting transition at 47.0 ± 1.0°C. These results indicate a stronger interaction for poly-L-arginine than for poly-L-lysine. The positive arginine side chains appear to interact with both the negative sulfate and carboxyl residues, while those of the lysines are involved only with the sulfates. Poly-L-ornithine at neutral pH shows no conformation directing interaction with chondroitin-6-sulfate, although a small proportion of α-helix is formed on dilution of the mixture with methanol. The extent of the interaction of cationic polypeptides with chondroitin-6-sulfate increases in the order poly-L-ornithine, poly-L-lysine, poly-L-arginine, i.e., in the order of increasing side-chain length.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.1973.360120603
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