A UV-SPECTROSCOPIC STUDY OF THE IN-VITRO ASSOCIATION OF TYPE I+III COLLAGENS WITH ELASTIN SOLUBILIZED PEPTIDES

The recently described in vitro association between elastin or elastin solubilized peptides (ESP) and type I + III collagens has been previo usly proved by scanning and transmission electron microscopy and by hi stological studies. The use of a UV-spectroscopic method corroborates the identity of the reaction and enable us to be more precise about it s mechanism. The collagen-ESP association is characterized by a 224 nm peak absorbance; the kinetic at this wavelength shows the same three characteristic phases as observed by turbidimetry curves for collagen fibrillogenesis. Spectroscopic studies concerning the effect of Ca2+ o n the reaction reveal that its presence decreases the lag phase and in creases the speed of the growth phase; without Ca2+ collagen can self- react but with a smaller amplitude. Our investigations confirm that, w hen present, ESP plays a conclusive role in collagen organization.