Preparation of cell-free extracellular matrix from human peripheral nerve

The extracellular matrix of human peripheral nerve, which is mainly basement membrane and fibrillar collagen, has been prepared by a procedure involving extensive detergent extraction of isolated endoneurium and perineurium obtained from various nerves. The ultrastructure of the isolated nerve extracellular matrix was indistinguishable from that seen in sections of intact nerve, indicating that the extraction procedure preserved the morphological integrity of these connective tissue components. The amino acid and carbohydrate compositions of the nerve extracellular matrix preparations were typically collagenous in nature containing a high content of glycine, proline, 4-hydroxyproline, and alanine and significant amounts of lysine and hydroxylysine. The preparations contained virtually no 3-hydroxyproline and low content of glucose and galactose compared to pure basement membranes, indicating that interstitial rather than basement membrane collagens predominated. This preparation appears well-suited to both the ultrastructural and biochemical study of the extracellular matrix of peripheral nerve.