The new study found that two amino acids are mary condos of molecular liquid phase separation


New research suggests that the amino acids arginine (pink) and lysine (green) can combine liquid phases with unique properties. Sincerely: Rachel Fisher

The past several years have brought increasing evidence that molecules inside our cells can self-organize into liquid droplets to facilitate various cellular activities that merge and break apart like water into oil. Now, a team of biologists from the Center for Advanced Science Research at The Graduate Center, CUNY (CUNY ASRC), have identified unique roles for the amino acids arginine and lysine to contribute to liquid phase properties and their regulation. Their findings are available online today Nature communication.


Known as liquid – liquid phase separation, the process allows certain molecules within a cell to lock themselves into membranous organisms to perform certain duties without interruption from other molecules. The mechanism can also allow molecules to form multiphase droplets, which are similar to a drop of honey inside a drop of oil surrounded by water to perform sophisticated jobs.

“This is a really exciting new research area because it exposes a key biological function that, when disturbed, can be at the root of the disease, particularly neurodegeneration in the form of ALS or Alzheimer’s,” major Investigator and Graduate Center, CUNY Biochemistry Professor Shana said Elbaum-Garfinkle, whose laboratory was studied by the CUNY ASRC Structural Biology Initiative. “With an understanding of how individual amino acids contribute to phase behavior, we can begin to investigate what is going wrong with liquid phase separation that may interfere with normal biological function and potential design treatments that can make the process Can modify. ”

Arginine (pink) dissolves and replaces lysine-containing droplets (green). These results present a new mechanism by which to design, control and / or interfere with existing new fluid phases. Sincerely: Rachel Fisher

Researchers have suspected for a while that arginine and lysine – two of the 20 amino acids that make up all the proteins – were responsible for regulating liquid phase dissociation, but they were not certain that each led to different in phase behavior. -How to contribute to generating different viscosity clusters of molecules in different communities.

“Arginine and lysine are both very similar amino acids in terms of being positively charged, but they differ in terms of binding capacity. We were really keen to understand what effect this difference would have on physical properties, such as viscosity. Or liquidity. They form drops, “Rachel Fisher, the paper’s first author and a postdoc in the album-Garfinkle Lab. “We also wanted to know how these differences manifest when the arginine and lysine systems are combined. Will there co-exist? When we saw that they did this, we wanted to understand that we were in this multi -How you can modify step behavior. ”

To answer their questions, Elbaum-Garfinkle’s team used a technique called microrheology — using small structures to examine material structures — to investigate the properties of arginine and lysine droplets and Investigation is done. They found that arginine-containing droplets were 100 times more viscous than lysine-containing droplets compared to condensed syrup or the difference between ketchup and oil. The viscosity difference is significant enough that if lysine and arginine polymers are combined, they do not mix. Instead, they form multi-step droplets that sit within each other like Dutch nesting dolls. Additionally, arginine has such strong bonding properties that under certain conditions it can compete with lysine and alter or dissolve lysine droplets. The researchers further identified ways to strike a balance between two-stage competition and coexistence. The results present a novel mechanism to design, control, or interfere with molecular liquid phases.


Trying to understand the internal design of cells


more information:
Nature communication, DOI: 10.1038 / s41467-020-18224-y

Provided by CUNY Advanced Science Research Center

Quotes: The new study found that two amino acids are mary condos of molecular liquid phase separation (2020, September 15). Retrieved 16 September 2020 from https://phys.org/news/2020-09-amino-acids-marie-kondo-molecular. .html

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