Physiologically Crowded Artificial Cells for Relevant Drug Screens

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In the crowded cell, nonspecific interactions between biomolecules alter biochemical equilibria. This matrix of weak nonspecific interactions is composed of hydrophobic, electrostatic, H-bonding, van der Waals, and steric interactions, and is “the dark matter of biology”. Inaccurate prediction of the behaviour of biomolecules inside cells hampers drug discovery: A high throughput drug screen against a purified target protein in dilute buffer ignores the presence of these weak interactions and results are less relevant. High throughput screens directly in cells are however more difficult to control, interpret and measure. PArtCell provides a key advance by combining the high level of control and ease of high-throughput screening on purified proteins, with the relevance of screening in the native environment. The aim is to construct artificial cells that provide a physiologically relevant drug-screening platform. We will achieve this aim by constructing artificial cells with a matrix of weak nonspecific interactions akin living cells as verified with newly engineered fluorescent probes. The probes measure hydrophobicity, electrostatics and steric effects, as well as the physicochemical state of pathogenic condensates, in healthy and stressed living cells. With this information, we will benchmark artificial cells. Drug screens are applied against pathogenic oligomers that we now can observe in these well-characterized artificial cells. This research will update textbook knowledge and provide the molecular origin of the matrix of weak nonspecific interactions in living cells. It provides a platform that allows screening against targets under native-like conditions not achievable with other methods. This research thus provides a new opportunity to screen drugs against diseases for which we have no cure yet.