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San Diego Company Reports Building Proteins Not Found In Nature

Synthorx details how it creates new proteins in this graphic, Aug. 19, 2015.

Photo by Synthorx, Inc

Above: Synthorx details how it creates new proteins in this graphic, Aug. 19, 2015.

San Diego-based Synthorx has claimed success at using synthetic DNA to create new kinds of proteins.

The company said Wednesday these proteins contain building blocks not found in nature, and they could eventually lead to "improved drugs, diagnostics, and vaccines.”

Scientists founded Synthorx last year after developing two synthetic DNA nucleotides. They say that discovery has expanded the genetic alphabet by taking nature's existing DNA bases — A, C, G and T — and adding the man-made pair X and Y to the mix.

On Wednesday, CEO Court Turner said Synthorx has now produced proteins not found in nature by loading their synthetic DNA into a bacteria.

"We've made the first proteins using Synthorx's unnatural base pairs, which we refer to as X and Y," Turner said.

The new proteins are a twist on an existing protein, according to Turner. But they contain amino acids not produced by natural DNA, due to its limited range of base pairs. Turner said adding only two new bases exponentially increases the number of amino acids at Synthorx's disposal.

"Proteins are made up of 20 natural amino acids, currently. What we're able to do is have access to 172 amino acids," said Turner.

Proteins perform important biological functions throughout the body, and biotech companies grow them as the basis for many drugs and vaccines.

Turner said the standard way of growing proteins is "almost like having a conversation when you only have 20 words to explain something. If you've got 172 words in your vocabulary, your stories are going to be a lot more interesting."

Synthorx has not published work on its first wave of novel proteins. The company is keeping this research proprietary in hopes of developing drugs based on such proteins, which they claim function differently from natural proteins.

UC San Diego synthetic biologist Neal Devaraj called Synthorx's work "a significant step forward."

In an email reacting to the news, he wrote, "This announcement indicates that unnatural DNA can be transcribed into RNA and ultimately translated into proteins containing unnatural amino acids. It will be exciting to see what applications the company envisions for its unnatural proteins."

Another researcher in the field, UC San Diego's Jeff Hasty, said it "seems like it could be huge."

In an email, Hasty said he'll be curious to see how exactly Synthorx plans to design proteins that prove useful.

"Maybe you can make some cool variants by sprinkling new bases into old proteins, then selecting with directed evolution," Hasty wrote. "The approach might open the door for some amazing assays."

Expectations are high for the year-old company. The journal Science called Synthorx's initial discovery of X and Y one of 2014's top breakthroughs.

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