Some observations on the amino-acid distribution of collagen, elastin and reticular tissue from different sources

Abstract

Collagen was prepared from ox-hide, elastin from ligamentum nuchae and reticular tissue from lymph nodes and fat deposits. Total N and amide N were determined and paper chromatograms of the hydrolysates examined. Examination of the titration curve and chromatogram of elastin indicates that several amino acids have still to be determined and that the reported values for arginine and alanine are low. Tissues from different sources which stain similarly may vary appreciably in composition. With the exception of a lower proline and hydroxy-proline content, the amino acid distribution of the reticular tissues was similar to that of collagen. Examination of chromatograms of the residues obtained by the exhaustive extraction of skin suggests that the elastic fibers of skin either differ from those of ligamentum nuchae with respect to amino acid composition or are less resistant to hot water.