In vitro Aggregation of Proteins from Insect Cuticle
Hillerton, J. Eric; Vincent, Julian F. V
Interactions between extracted proteins from various types of insect cuticle have been investigated in vitro. Proteins from pharate sclerites aggregate reversibly in simple buffer as a response to temperature changes; they are soluble at lower temperatures. The temperature at which aggregation commences differs for each source of protein. Proteins from pliant cuticles do not show such aggregation. They, however, show specific aggregations on urea-gradient gel electrophoresis. Such aggregations were not found for sclerite proteins. The types of aggregation are probably related to the relative hydrophobicity of the protein. Such interactions may indicate physical phenomena related to assembly of pharate cuticle, post-ecdysial plasticisation of these cuticles and dehydration prior to irreversible stabilisation of all cuticles. It is emphasised that the in vitro system can only model the in vivo processes.