Properties of insoluble collagen from three different types of muscles

1. Lyotropic solubilization of insoluble collagen from heart, M. longissimus dorsi and M. semimembranosus offers differently polymerized structures. In M. semimembranosus and in heart muscle the degree of polymerization is the highest, whilst in the solubilized portion of M. longissimus dorsi considerable proportions of alpha-and beta-chains can be observed. 2. All the polymeric structures can be broken down by pepsin and dithiothreitol treatment. 3. The proportion of collagen type I to III varies in different muscles. Collagen type I constitutes a considerable portion of the collagenous core in M. longissimus dorsi and in heart muscle, whilst in M. semimembranosus the predominating type is collagen type III.