Unexpected original property of elastin derived proteins: spontaneous tight coupling with natural and synthetic polymers

Elastin fibres can be decomposed into their constituting proteins using several processes; in particular by saponification of some bonds with KOH in aqueous tertiobutyl alcohol, elastin solubilized proteins - ESP- of 10 to 200 KDa were produced with a good yield (70-80%). It is demonstrated that some of these proteins were capable of tightly re-associating with the native elastin fibres and remained bound on the fibres, in spite of several drastic washes using 1 M Guanidinium, HCl at 37°C for 1 h. At pH 4-5, approximately 30-40 μg ESP were retained per mg elastin. The same association is also shown to occur, under similar conditions, with Poly-ethylene-terephtalate, Poly-hexamethylene diamine-adipic acid but not with polyurethanes. The optimal conditions of the coupling were described as depending on ESP concentration, time, pH, ionic strength and Ca++. It was also shown that opposite pH conditions, i.e. pH 14, 0.5 M NaOH, could allow the retained proteins to desorb from polyesters. Hence, it will be possible to determine the sort of proteins which could be involved.