Nav: Home

Cold-adapted enzymes can transform at room temperature

May 26, 2020

Enzymes from cold-loving organisms that live at low temperatures, close to the freezing point of water, display highly distinctive properties. In a new study published in Nature Communications, scientists at Uppsala University have used large-scale computations to explain why many cold-adapted enzymes stop functioning at around room temperature.

Enzymes are the "machines" that maintain metabolism in all living cells, but unfortunately all biochemical reactions normally stop at low temperatures. Evolution has solved this problem by developing cold-adapted enzymes in species whose internal cell temperature is the same as in the cold external environment. This applies to countless organisms, from bacteria to certain plants and cold-blooded vertebrates, such as fish that live in very cold water. These cold-adapted enzymes have special thermodynamic properties that enable them to function in freezing conditions. Evidently, they also melt at lower temperatures than ordinary enzymes; but it makes no difference if they melt at approximately 40 degrees Celsius, since they never need to work in such a warm environment.

However, one major unsolved enigma has been why many cold-adapted enzymes stop functioning even at around room temperature, long before they start melting. Researchers Jaka Socan, Miha Purg and Johan Åqvist have now, for the first time, succeeded in explaining this by means of extensive computer simulations.

The scientists simulated the chemical reaction in a starch-degrading enzyme from an Antarctic bacterium at various temperatures, and compared this with calculations relating to the same enzyme from an ordinary, warm-blooded pig. The Antarctic enzyme then proved to start breaking up locally even at room temperature, and this defect makes the starch molecules adhere much less well to the enzyme. This phenomenon gives rise to a maximum reaction speed at 25 degrees Celsius, and takes place at some 15 degrees Celsius below the melting point. In the pig enzyme, on the other hand, the reaction speed just keeps increasing until the enzyme finally melts at roughly 60 degrees Celsius.

With computer calculations, it is thus possible to identify which parts of the cold-adapted enzymes give rise to their special properties.

"Both our new results and earlier ones from computer simulations of various cold-adapted enzymes, and their mutants, show that we've now reached a stage where one can rationally redesign enzymes to change their properties in a predictable way. This approach has long been an aim, but to date it hasn't been able to compete with random laboratory evolution of enzymes, for which Frances Arnold was awarded the Nobel Prize in 2018," says Johan Åqvist, Professor of Theoretical Chemistry at the Department for Cell and Molecular Biology, Uppsala University.

Uppsala University

Related Enzymes Articles:

Cold-adapted enzymes can transform at room temperature
Enzymes from cold-loving organisms that live at low temperatures, close to the freezing point of water, display highly distinctive properties.
How enzymes build sugar trees
Researchers have used cryo-electron microscopy to elucidate for the first time the structure and function of a very small enzyme embedded in cell membranes.
Energized by enzymes -- nature's catalysts
Scientists at Pacific Northwest National Laboratory are using a custom virtual reality app to design an artificial enzyme that converts carbon dioxide to formate, a kind of fuel.
Mathematical model reveals behavior of cellular enzymes
Mathematical modeling helps researchers to understand how enzymes in the body work to ensure normal functioning.
While promoting diseases like cancer, these enzymes also cannibalize each other
In diseases like cancer, atherosclerosis, and sickle cell anemia, cathepsins promote their propagation.
Researchers finally grasp the work week of enzymes
Scientists have found a novel way of monitoring individual enzymes as they chomp through fat.
New study looks to biological enzymes as source of hydrogen fuel
Research from the University of Illinois and the University of California, Davis has chemists one step closer to recreating nature's most efficient machinery for generating hydrogen gas.
How oxygen destroys the core of important enzymes
Certain enzymes, such as hydrogen-producing hydrogenases, are unstable in the presence of oxygen.
How nature builds hydrogen-producing enzymes
A team from Ruhr-Universität Bochum and the University of Oxford has discovered how hydrogen-producing enzymes, called hydrogenases, are activated during their biosynthesis.
New family on the block: A novel group of glycosidic enzymes
A group of researchers from Japan has recently discovered a novel enzyme from a soil fungus.
More Enzymes News and Enzymes Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Our Relationship With Water
We need water to live. But with rising seas and so many lacking clean water – water is in crisis and so are we. This hour, TED speakers explore ideas around restoring our relationship with water. Guests on the show include legal scholar Kelsey Leonard, artist LaToya Ruby Frazier, and community organizer Colette Pichon Battle.
Now Playing: Science for the People

#568 Poker Face Psychology
Anyone who's seen pop culture depictions of poker might think statistics and math is the only way to get ahead. But no, there's psychology too. Author Maria Konnikova took her Ph.D. in psychology to the poker table, and turned out to be good. So good, she went pro in poker, and learned all about her own biases on the way. We're talking about her new book "The Biggest Bluff: How I Learned to Pay Attention, Master Myself, and Win".
Now Playing: Radiolab

First things first: our very own Latif Nasser has an exciting new show on Netflix. He talks to Jad about the hidden forces of the world that connect us all. Then, with an eye on the upcoming election, we take a look back: at two pieces from More Perfect Season 3 about Constitutional amendments that determine who gets to vote. Former Radiolab producer Julia Longoria takes us to Washington, D.C. The capital is at the heart of our democracy, but it's not a state, and it wasn't until the 23rd Amendment that its people got the right to vote for president. But that still left DC without full representation in Congress; D.C. sends a "non-voting delegate" to the House. Julia profiles that delegate, Congresswoman Eleanor Holmes Norton, and her unique approach to fighting for power in a virtually powerless role. Second, Radiolab producer Sarah Qari looks at a current fight to lower the US voting age to 16 that harkens back to the fight for the 26th Amendment in the 1960s. Eighteen-year-olds at the time argued that if they were old enough to be drafted to fight in the War, they were old enough to have a voice in our democracy. But what about today, when even younger Americans are finding themselves at the center of national political debates? Does it mean we should lower the voting age even further? This episode was reported and produced by Julia Longoria and Sarah Qari. Check out Latif Nasser's new Netflix show Connected here. Support Radiolab today at