Extraction of sericin protein from Bombyx mori L. cocoon (Race Nistari)

Abstract

Sericin is a glue protein synthesized in the middle silk gland of the silkworm Bombyx mori L. Sericin exhibits several valuable biological and physicochemical properties which may vary according to the method extraction. The aim of the present study is to find out suitable extraction protocol for extraction of sericin from Nistari cocoon (Traditional race) and to analyze the molecular mass of the same by SDS-PAGE. In the present study, sericin is extracted employing different concentrations of urea, NaOH, Na2CO3, Triton X-100, LiBr, CaCl2 and with different buffers. Among these, the highest yield was obtained when sericin was extracted with Sodium hydroxide solution followed by Sodium carbonate solution. However, the extract when run on a SDS-PAGE exhibited smears, indicated degradation of the sericin. Treatment with urea and Triton X-100 were found to be most effective in comparison in terms of both quality and quantity. SDS-PAGE profile of sericin extracted with 6 M urea and Triton X-100 exhibited clear and distinguishable bands within the ranges of 10 to >225 kDa and 25-75 kDa respectively.