Analysis of Plant Proteins Advances Understanding of Photosynthesis

Plants release oxygen by absorbing carbon dioxide and breaking down water using sunlight through photosynthesis. However, little is known about the mechanics of how plants create oxygen during photosynthesis. Scientists at Louisiana State University (LSU) studied the cellular system responsible for creating oxygen during photosynthesis called Photosystem II. They analyzed two proteins that are critical to creating oxygen, and how they connect and interact.

Manjula Mummadisetti, a graduate student at LSU's Department of Biological Sciences, created a 3D model of the two critical proteins, PsbP and PsbQ, to see how they function. She isolated the chloroplasts from spinach, and treated them with a chemical detergent to extract a high concentration of Photosystem II. She then used high-resolution mass spectrometry to see where the two proteins overlap and connect.

According to LSU Professor Terry Bricker, the two proteins are like parts of a car that enable oil to reach the engine. In plants, the "oil" is calcium and chloride and the "fuel" is water and sunlight. The structure of PsbP and PsbQ facilitates the efficient use of calcium and chloride in a plant, enabling it to produce oxygen.

For more details about this work, read the LSU news release at: http://www.lsu.edu/ur/ocur/lsunews/MediaCenter/News/2014/10/item73226.html.