Structure characterization and antioxidant properties of proteins extracted from the larva of Bombyx mori L.

Abstract

Purpose: To explore the structural characteristics and antioxidant properties of proteins extracted by salt extraction and ammonium sulfate precipitation (SEAP) from the larvae of Bombyx mori L. (PLB) that died due to infection with Beauveria bassiana (Bals.) Vuill. Methods: The extraction yield of PLB was measured, and protein patterns were examined by SDS-PAGE. The amino acid composition of PLB was analyzed using an automatic amino acid analyzer while the structural characteristics of PLB were analyzed by Fourier transform infrared (FT-IR) and UV techniques. In addition, the antioxidant properties of PLB were investigated in vitro. Results: The extraction yield of PLB was 2.16 ± 0.04 %. PLB protein was mainly present in 10 – 20 and 25 – 35 kDa fractions. PLB consisted of 15 types of amino acids. Glu (12.45 ± 0.06), Ala (6.87 ± 0.11) and Val (4.55 ± 0.11) contents of PLB were significantly (p < 0.05) higher relative to that of other amino acids. PLB exhibited the FT-IR and UV spectra characteristics of proteins. In addition, PLB exhibited significant antioxidant effects (p < 0.05). Conclusion: The results indicate that PLB exhibits significant antioxidant effects and may be suitable for development into antioxidant drugs.