Studies on the Structure, and Mechanism of Degradation of Silk Fibroins

Part 3. Main Amino Acids Distribution of Silk Fibroins Degradated with Dilute Acid and Alkali

Abstract

Deguminated fibroin fibers were partially degradated and stepwisely fractionated with dilute HCl and NaOH, and the distributions of total nitrogen, glycine, alhnine, tyrosine, serine and threonine in these fractions and untreated fibroin were determined. A little heterogeneity of the distributions of these amino acids was observed. This fact might be attributed to the foreign protein which could not be separated from fibroin molecule by the ordinary procedure, or to the shape or construction factors of fibers.
It seems that the mode of peptide linkages of amino acids, various sizes side-chains in fibroin molecules, which have not only factor of so-called crystalline and amorphous regions defined by the treatments with acid and alkali.
The phenomena of the degradation of fibroin fibers, any way, were seemed to be controlled by complicated factors contrasting with cellulose fibers which have simple glucosidic linkages.