The proteolytic digestion of ox neurofilaments with trypsin and α-chymotrypsin

摘要: Brief digestion of ox neurofilaments with trypsin liberates fragments that are soluble and have molecular weights ranging from 164 000 to 97 000. Peptide fingerprinting indicates these regions, termed the tryptic head-regions, arise 205 000- 158 000-mol.wt. components triplet. The remains parent polypeptides sediment normal filaments been tail-regions. Digestion chymotrypsin also (chymotryptic head-regions) but mol.wts. 171 119 000, though they too originate higher-molecular-weight triplet polypeptides. Tryptic chymotryptic head-regions extensive homology, a low (less than or equal 20%) helix content. Electron microscopy shows rapidly reduces length filaments, probably because this enzyme preferentially attacks 72 polypeptide. In contrast, brief does not reduce filament even more 90% two cleaved. These results indicate backbone native is formed polypeptide together tail-regions corresponding components, which can represent nearly 75% each molecule, necessary for preserving therefore good candidates being side arms connect in nerve cells.