Silk Protein Sericin Accelerates Proliferation of Various Mammalian Cells

Abstract

Sericin protein derived from silkworm cocoon was added to the culture of various mammalian cell lines including human hepatoblastoma HepG2, human fibroblasts and so on. The proliferations of all cell lines tested were accelerated in the presence of sericin and its mitogenic activity was comparable to that of bovine serum albumin (BSA), one of the best supplements for the culture medium. Sericin derived from silkworm cocoons would be a preferable supplement for culture media because the risk of infection to human was not reported, while BSA is obtained from bovine serum and the risk of infection such as bovine spongiform encephalopathy cannot be avoided. Recombinant sericin peptides synthesized by E. coli (1) also stimulated the growth of hybridoma as well as sericin derived from silkworm did. These results indicate that sericin is a novel and suitable mitogenic supplement for mammalian cell culture.