Lipids are integral part of the body and are essential for functioning of the body at molecular level. Researchers have been utilizing fluorescent proteins to visualize lipid molecules. A professor at University of Illinois, Chicago demonstrated the first successful quantification of membrane lipids in a living cell in real time.
Lipids constitute a broad group of naturally occurring molecules which include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The main biological functions of lipids include energy storage, as structural components of cell membranes, and as important signaling molecules.Functions of lipids in the body are:
Membranes: The glycerophospholipids are the main structural component of biological membranes, such as the cellular plasma membrane and the intracellular membranes of organelles.
Energy storage: Triacylglycerols, stored in adipose tissue, are a major form of energy storage.
Signaling: Lipid signaling may occur via activation of G protein-coupled or nuclear receptors identified as signaling molecules and cellular messengers.
Lipids help regulate important cellular processes such as cell proliferation and immune response. Problems with lipid signalling have been linked with a number of diseases including cancer, diabetes, autoimmune diseases, and inflammatory conditions. “Lipid molecules on cell membranes can act as switches that turn on or off protein-protein interactions affecting all cellular processes, including those associated with disease.”
Biosensor for lipid levels using modified proteins to fluoresce
Wonhwa Cho, a chemistry professor at the University of Illinois at Chicago developed a biosensor using modified proteins to...
fluoresce and act as sensors for lipid levels. The technique allows quantification by using a hybrid protein molecule that fluoresces only when it binds specific lipids.
He worked with a lipid known as PIP2 — an important fat molecule involved in many cellular processes. The sensor binds to PIP2 and gives a clear signal that can be quantified through a fluorescent microscope. This results in the quantification of membrane lipids in a living cell in real time. The protein was engineered in such a way that it became very stable, behave well, and specifically recognize a particular lipid. Cho now plans to create a tool kit of biosensors to quantify most of the lipids.
He said: “We’d like to be able to measure multiple lipids, simultaneously. It would give us a snapshot of all the processes being regulated by the different lipids inside a cell.”
The quantification of lipid molecules utilizing the fluorescent proteins looks like a significant development. We hope to see applications/ products like biosensors based on the research.