Isolation of peripheral nerve collagen.

A new method for the isolation of high yields of collagen from human peripheral nerve is described. A major technique adopted in the present work is sedimentation of the tissue homogenates in a sucrose density gradient. The defatted fibrous material isolated after the removal of myelin was shown to be a relatively pure collagenous substance by amino acid analysis, indicating that the removal of noncollagenous proteins, especially glycoproteins, from collagen fibrils was effectively achieved by this method. The yield of collagen at this step was more than 90% of the total collagen in peripheral nerve. Subsequent extractions with solutions of neutral saline and sodium citrate were found to give further purification of the collagenous protein. The collagens from embryonic peripheral nerves were composed of Type I and III collagens, while Type III collagen was found to be less abundant in adult peripheral nerves.