5] Characterization of fibrous forms of collagen

Abstract

Publisher Summary Collagen fibers can be studied in tissues or as fibers reprecipitated from solutions of purified collagen. The biochemical data establishing differences in the collagenous and noncollagenous components of various connective tissues has clarified the need to compare structures of fibrils in different tissues and of fibers reprecipitated from different genetic types of collagen. Such investigations have been carried out in this chapter using electron microscopy and X-ray diffraction on both native tissues and reprecipitated fibers. From electron microscopy, one gets an image of the fibril showing the gap: overlap regions (by negative staining) or the distribution of charged residues (by positive staining). In examination it is found that the SLS banding patterns of different genetic types of collagen can be distinguished, but no differences can be seen in the native-type fibrils reprecipitated from purified type I, type II, or type III collagens. In addition, X-Ray diffraction studies provide information on the axial fibril structure and the lateral packing of molecules in the fibril. Examination of various tissues and reprecipitated fibers has indicated that the X-ray patterns vary from the well-studied one of rat tail tendon.