Native structure and degradation pattern of silk sericin studied by 13C NMR spectroscopy

The Sericin Hope silkworm was used as a sericin source to investigate the structure of native sericin before spinning and after spinning using 13C solution and 13C solid state NMR. The 13 solid-state NMR spectrum of the Sericin Hope cocoon after spinning was observed. Sericin solution regenerated from the Sericin Hope cocoon under mild conditions exhibited distinct protein bands by electrophoresis demonstrating that no thermal degradation occurred during preparation. Results show that sericin forms a largely random coil structure in the native state in MSG and undergoes to structural changes during the spinning of the silkworm.