X-ray analysis of enzymically purified elastin from bovine ligamentum nuchae.

Insoluble elastin has been isolated from bovine ligamentum nuchae by treatment with quanidine and dithiothreitol followed by digestion with collagenase, purified by affinity chromatography. The preparation was subjected to both wide- and low-angle X-ray analysis. The wide-angle diffraction patterns of relaxed and stretched specimens showed only two broad diffraction rings, corresponding to spacings of 4.5 and 9.3 A. No significant reflections were visible in the low-angle diffraction pattern of unstretched specimens, but on stretching an equatorial reflection was produced, corresponding to spacings of between 45 and 50 A.