Isolation, purification and characterization of silk protein sericin from cocoon peduncles of tropical tasar silkworm, Antheraea mylitta.
A high molecular weight water-soluble glue protein, sericin was identified in the cocoon peduncle (a strong thread connecting the cocoons to the branches of the tree with a ring) of the tropical tasar silkworm, Antheraea mylitta. The sericin was isolated by 8M urea containing 1% sodium dodecyl sulfate and beta-mercaptoethenol (2%) or by 1% sodium chloride. The protein was purified by gel filtration chromatography. In SDS-PAGE, a single band of approximately 200kDa was detected both in non-reducing and reducing conditions. Amino acid analysis showed that the protein is enriched in glycine and serine. There is a slight difference observed in amino acid composition between the sericin from cocoon peduncle and cocoon of A. mylitta. Secondary structure estimation by circular dichroism spectrometry showed 36.7% beta-sheets, 52.7% random coils, 10.6% turns and no helices.
Dash
Rupesh
R
Department of Biotechnology, Indian Institute of Technology, Kharagpur 721302, India.
Mukherjee
Soumen
S
Kundu
S C
SC
D000818:Animals; D012831:Bombyx; D002850:Chromatography, Gel; D002942:Circular Dichroism; D004591:Electrophoresis, Polyacrylamide Gel; D019476:Insect Proteins / Q000378:metabolism; D008623:Mercaptoethanol / Q000737:chemistry; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D047030:Sericins / Q000737:chemistry*; D047011:Silk
D019476:Insect Proteins; D047030:Sericins; D047011:Silk; D008623:Mercaptoethanol