Self-Organization of Protein Fibers in Weightlessness
It is currently hypothesized and widely believed that the growth of self aggregating protein chains such as amyloid fibers has a direct effect on the function of the human brain. We hypothesized creating self-assembling protein in weightlessness would allow the aggregation to continue for a longer period of time in solution without sedimentation. When protein de-natures and self-organizes into amyloid fibers the effect can be detrimental. Some neurodegenerative diseases, such as Alzheimer’s and Dementia, are believed to be caused by the collection of these fibers made from proteins such as tau and amyloid-β. For the purpose of this experiment, lysozyme is employed as a protein that has been shown to replicate the aggregation morphologies shown by tau and amyloid-β in the brain under certain conditions. For this experiment lysozyme is incubated with a concentration of 20 mg/ml at 55!C and pH 2.5 in a glycine-HCl buffer solution. During the experiment reliable materials and methods are found for lysozyme protein fiber creation and documented. This method is replicated in weightlessness on the International Space Station (ISS). The construction of two identical NanoLabs, one sent to the ISS and one setup in the laboratory at Florida Tech, was necessary to test the changes weightlessness has on the initial stages of protein aggregation. The flight experiment and the observed physical changes of fibers formed in weightlessness are discussed in detail. The results of weightless fiber formation showed differences in morphology and inhibition of assembly rate. Data analysis is presented with observations, conclusions from the research conducted, and implications for future improvements on the experimental model to refine results.