Effects of UV irradiation on the molecular weight of spider silk

Abstract

The molecular weight of the Nephila clavata spider dragline was determined to be 272±14 kDa using a SDS-PAGE method. The effects of ultraviolet (UV) irradiation on the molecular weight of the spider dragline were studied and compared with that of silkworm silk. The band densities observed using SDS-PAGE for the spider dragline and silkworm silk decreased with the UV irradiation time, suggesting decomposition due to the cleavage of protein chain molecules. It was found that the rate constant of degradation due to UV irradiation for the silkworm silk was larger by 1.7 than that for the N. clavata spider dragline. This result indicates that the N. clavata spider dragline was 1.7 times more resistant to UV irradiation than silkworm silk. Copyright © 2013 The Society of Polymer Science, Japan.