Can Life Exist Without Water? A Data-Driven Approach

Abstract

Life-as-we-know-it could not exist without water. In fact, living cells survive in environments mainly constituted by water. Cellular shape and functionality are determined by the presence of both the plasma and the cytoplasmic membrane, which define all the necessary compartments for the organization of the cellular matter, as well as to prevent mixing of the cell with its external environment. To this aim, living organisms typically exploit biological lipids, amphiphile molecules comprising a strongly polar head group and one or more long hydrocarbon tails. In aqueous solutions, these amphiphilic molecules tend to aggregate driven by ’like-to-like’ interactions that are usually referred to as the hydrophobic effect. Within this general framework, water is unique because it forms hydrogen bonds with itself as well as with the polar moiety of the amphiphilic molecule. While this marvelous balance is the result of millions of years of evolution, it is possible to imagine that a different type of life could be achieved in different biological environments under different conditions, such as those present in other planets of our universe. Although water has been detected in various thermodynamic states in our solar system, an alternative scenario suggests the possibility of using polarity-inverted membranes in non-polar solvents, such as the hydrocarbons frequently found in earth-like systems. Motivated by this idea, a number of related studies have recently been conducted. In this contribution, I will describe recent efforts by our group along these lines, as well as the possibility of leveraging on recent achievements of AlphaFold that highlighted the power of data-driven approaches hinging on artificial intelligence/machine learning techniques.