“They are investigating areas that are largely unexplored.” Sol GrunerI study molecular biophysics at Cornell University. He was consulted for the study but was not a co-author.
Plasmalogen lipids are also present in the human brain, and their role in deep-sea membranes may help explain aspects of cell signaling. More immediately, this research will reveal new ways in which life has adapted to the most extreme conditions of the deep ocean.
madness in the membrane
The cells of all life on Earth are surrounded by fatty molecules known as lipids. When you put lipids in a test tube and add water, they automatically line up back to back. The greasy, water-loving tails of the lipids mix together to form the inner layer, and the water-loving heads line up together to form the outer layer. part of the thin membrane. “It’s like oil and water separating in a dish,” Winikoff says. “That’s universal for lipids, and that’s how lipids work.”
For cells, the outer lipid membrane provides structure and acts as a physical barrier to keep the inside of the cell inside, similar to the outer wall of a house. However, the barrier cannot be too strong. Barriers are studded with proteins and require proteins. They wiggle space to carry out various cellular tasks, such as transporting molecules across membranes. Cell membranes can also peel off, releasing chemicals into the environment and fusion again.
Therefore, for a membrane to be healthy and functional, it must be robust, fluid, and dynamic at the same time. “The membrane is balanced on the edge of stability,” Winikoff said. “Even though it has this very well-defined structure, all the individual molecules that make up the sheets on either side are constantly flowing around each other. It’s actually a liquid crystal.”
One novel property of this structure is that the central part of the membrane is highly sensitive to both temperature and pressure, much more so than other biomolecules such as proteins, DNA, and RNA. Yes, he says. For example, when you cool a lipid membrane, like when you put olive oil in the refrigerator, the molecules move more slowly and “eventually they stick together,” Winikoff says. “Biologically, that’s generally a bad thing.” Metabolic processes stop. The membrane may crack and the contents may leak.
To avoid this, many cold-adapted animals have membranes composed of mixtures of lipid molecules with slightly different structures to keep the liquid crystals flowing even at low temperatures. Because high pressure slows the flow of membranes, many biologists assumed that deep-sea membranes were built in a similar way.
