“They are looking into an area that, to a large degree, has not been explored,” stated Sol Gruner, who researches molecular biophysics at Cornell College; he was consulted for the research however was not a co-author.
Plasmalogen lipids are additionally discovered within the human mind, and their position in deep-sea membranes may assist clarify facets of cell signaling. Extra instantly, the analysis unveils a brand new approach that life has tailored to probably the most excessive circumstances of the deep ocean.
Insane within the Membrane
The cells of all life on Earth are encircled by fatty molecules often known as lipids. In the event you put some lipids in a check tube and add water, they routinely line themselves up again to again: The lipids’ greasy, water-hating tails commingle to type an internal layer, and their water-loving heads organize collectively to type the outer parts of a skinny membrane. “It’s just like oil and water separating in a dish,” Winnikoff stated. “It’s universal to lipids, and it’s what makes them work.”
For a cell, an outer lipid membrane serves as a bodily barrier that, just like the exterior wall of a home, supplies construction and retains a cell’s insides in. However the barrier can’t be too stable: It’s studded with proteins, which want some wiggle room to hold out their numerous mobile jobs, comparable to ferrying molecules throughout the membrane. And generally a cell membrane pinches off to launch chemical substances into the atmosphere after which fuses again collectively once more.
For a membrane to be wholesome and practical, it should subsequently be sturdy, fluid, and dynamic on the similar time. “The membranes are balancing right on the edge of stability,” Winnikoff stated. “Even though it has this really well-defined structure, all the individual molecules that make up the sheets on either side—they’re flowing around each other all the time. It’s actually a liquid crystal.”
One of many emergent properties of this construction, he stated, is that the center of the membrane is very delicate to each temperature and strain—way more so than different organic molecules comparable to proteins, DNA or RNA. In the event you calm down a lipid membrane, for instance, the molecules transfer extra slowly, “and then eventually they’ll just lock together,” Winnikoff stated, as whenever you put olive oil within the fridge. “Biologically, that’s generally a bad thing.” Metabolic processes halt; the membrane may even crack and leak its contents.
To keep away from this, many cold-adapted animals have membranes composed of a mix of lipid molecules with barely completely different constructions to maintain the liquid crystal flowing, even at low temperatures. As a result of excessive strain additionally slows a membrane’s circulate, many biologists assumed that deep-sea membranes had been constructed the identical approach.
