Interaction between the alpha 1 chain of rat tail collagen and sodium dodecyl sulfate with reference to its behaviour in SDS-polyacrylamide gel electrophoresis.

The interaction between the alpha 1 chain of rat tail collagen and sodium (SDS) was studied to provide knowledge necessary to understand the behavior of the complex between them in a molecular sieving technique such as SDS-polyacrylamide gel electrophoresis. Measured properties include binding isotherm, CD spectrum, viscosity and behavior in free boundary electrophoresis, gel electrophoresis and high-pressure silica gel chromatography. The complex differed in most respects from the complexes between SDS and polypeptides derived from water-soluble globular proteins, reflecting its peculiar amino acid composition. THe hydrodynamically effective volume of the SDS-alpha 1 chain complex was the most significantly different among the properties studied. The complex of the alpha 1 chain consisted of 1052 amino acid residues and was found to have the same effective volume as that of a standard polypeptide consisting of about 800 residues. The abnormal behaviour of the SDS-alpha 1 chain complex was interpreted on the basis of these results.