Solute effects on the mechanical properties of arterial elastin

We have examined the effects of various solutions (SDS, DMSO, NaCl) on the swelling and mechanical properties of arterial elastin. Our results indicate that SDS-swollen elastin is stiffer, stronger, and appears to fail at smaller extensions than water-swollen elastin. In order to determine if these changes in mechanical properties are due to swelling changes or to a specific effect of SDS bound to the elastin network, we studied the effect of DMSO on the mechanical properties of elastin. DMSO swells elastin to the same extent as 0.1 M SDS, but DMSO is uncharged and probably does not interact directly with the elastin protein. The data for DMSO-swollen elastin corrected for swelling changes are virtually identical to those of water-swollen elastin but significantly different from those of SDS-swollen elastin. Thus, there is apparently a specific SDS effect, and this effect probably arises from the high negative charge density due to bound SDS. Lastly, studies of changes induced by sodium chloride concentrations in the physiological range indicate that there is no significant change in stiffness, strength, or extensibility due to increased NaCl levels.