Binding Affinity Of Tau to Microtubules In Vitro

Alzheimer’s is a disease that affects millions of people in the world and is associated with the malfunction of the Tau protein. In its normal state, the Tau protein acts as a stabilizing agent to microtubules – important components of the neural cytoskeleton. The goal of our research is to lay down a basic framework of how the Tau protein interacts with microtubules in vitro. We combined different ratios of the Tau protein and the protein Tubulin in order to understand at what levels the tau concentration is too high to bind to microtubules, and what the minimum necessary concentration of Tau needs to be to still get maximum polymerization. We studied 4 out of the 6 naturally occurring isoforms of the protein: 3RS, 3RL, 4RS, and 4RL, and conducted our research using the common biochemistry technique SDS-PAGE. Interpreting the relative intensities of the protein markers on the SDS-PAGE gels led us to conclude that the binding affinity of the Tau protein is a non-linear trend, and that different isoforms of Tau have different binding affinities to microtubules. This basic framework gives us a greater understanding of how the protein behaves, which is valuable to potential future research that will target curing Alzheimer’s and other diseases associated with Tau protein malfunction.