Chemistry researchers at the Technion-Israel Institute of Technology in Haifa have discovered that processes related to producing energy by photosynthesis and cell respiration are affected by the composition of the cell membrane.
Assistant Prof. Nadav Amdursky of the Technion’s Schulich Faculty of Chemistry has developed a technology for the study of membrane proton transitions related to the production of energy in cellular respiration and photosynthesis processes. The study, conducted with collaborators from the UK and Finland, was recently published in the Proceedings of the American Academy of Sciences (PNAS) with the title “Exploring fast proton transfer events associated with lateral proton diffusion on the surface of membranes.”
Energy is an essential resource in the animal world, without which there can be no life. All animals and plants use the same type of energy, the adenosine triphosphate (ATP) molecule – a nucleotide known in biochemistry as the “molecular currency”, able to store and transport chemical energy within cells. The synthesis of ATP takes place during the photosynthesis or the cellular respiration processes, where the energy of sunlight or chemical energy of nutrients, respectively, is used for the production of ATP. The molecular mechanism for ATP synthesis is based on a membrane protein. The protein’s activity can be linked to the action of a nanometer motor powered by protons. When the engine gets fuel – protons – the protein parts move.
The general action of this protein engine is to create ATP. But how do the protons reach the protein? This question has not yet been fully resolved, because the scope of the proton-movement process in time and space is tiny; a few nanometers every few nanoseconds.
The technology developed by Assistant Prof. Amdursky to study this tiny and fast process occurs on the surface of membranes, and is based on an original molecular probe that attaches to the membrane and releases a proton whenever light (photons) hits it. In other words, it is a technology that can produce the fuel to create the energy “currency” on the surface of membranes with the help of light.
The molecular probe developed at the Technion is based on a very intriguing chemical molecule called photo-acid. When this molecule absorbs light – and only then – its chemical properties change, and it becomes a strong acid. The main characteristic of any strong acid is the speedy release of a proton in an aqueous environment, and this is what happens here as well.
The research was supported by the Chaya Career Advancing Chair, the Russell Berrie Nanotechnology Institute and the Grand Technion Energy Program.
Assistant Prof. Nadav Amdursky
Illustration: A computer simulation (molecular dynamics) showing the location of the molecular probe on the surface of different membranes with different lipid compositions
Link to the article https://www.pnas.org/content/116/7/2443