Protein

Jiggly gelatin: Good workout snack for athletes?

jello

Downing a gelatin snack along with some O.J. before exercising might limit injury to bones and muscles, a new study shows. This means the jiggly snack might have health benefits.

Gelatin is an ingredient made from collagen, the most abundant protein in an animal’s body. (Most Americans know gelatin as the basis of Jell-O, a popular treat.) Collagen is part of our bones and ligaments. So Keith Baar wondered if eating gelatin might help those important tissues. As a physiologist at the University of California, Davis, Baar studies how the body works.

To test his idea, Baar and his colleagues had eight men jump rope for six minutes straight. Each man did this routine on three different days. An hour before each workout, the researchers gave the men a gelatin snack. But it differed slightly each time. On one day it had a lot of gelatin. Another time, it had just a little. On a third day, the snack contained no gelatin.

Neither the athletes nor the researchers knew on which day a man got a particular snack. Such tests are known as “double blind.” That’s because both the participants and scientists are “blind” to the treatments at the time. That keeps people’s expectations from affecting how they initially interpret the results.

On the day the men ate the most gelatin, their blood contained the highest levels of collagen’s building blocks, the researchers found. That suggested that eating gelatin might help the body make more collagen.

The team wanted to know whether these extra collagen building blocks might be good for ligaments, a tissue that connects bones. So the scientists collected another blood sample after each rope-skipping workout. Then they separated out the blood’s serum. This is a protein-rich liquid left behind when the blood cells are removed.

The researchers added this serum to cells from human ligaments that they were growing in…

DNA may offer rapid road to Zika vaccine

Zika DNA vaccine
A Zika vaccine that’s made of DNA could be a safe and fast way to protect people from the virus, which can cause birth defects.

GIVE IT A SHOT

Last August, scientists injected a potential vaccine for Zika virus into a human being — just 3½ months after they had decided exactly what molecular recipe to use.

In the world of vaccine development, 3½ months from design to injection is “warp speed,” says vaccine researcher Nelson Michael of the Walter Reed Army Institute of Research in Silver Spring, Md. Clinical trials can take years and epidemics can burn out before vaccines make it to doctors’ shelves. Even vaccine creation is typically sluggish.

But in this case, the vaccine is a bit of DNA, which means scientists can get moving fast. Unlike some traditional methods, DNA vaccines don’t use dead or weakened viruses. Instead, they rely on a snippet of genetic material. This “naked” DNA carries, for example, the blueprints for Zika proteins. It’s just a long sequence of DNA blocks.

With DNA vaccines, “it’s easy to move very quickly,” says Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases in Bethesda, Md. “All you need to do is get the right sequence, and Bingo! — you’re there.”

Historically, though, DNA vaccines have been deviled with drawbacks. “They work absolutely fantastically in mice,” says infectious diseases physician Anna Durbin of Johns Hopkins Bloomberg School of Public Health. But “they fail miserably when we use them in humans.”

Researchers at the infectious diseases institute will soon begin the second phase of human clinical trials for a DNA vaccine candidate for Zika, vaccine clinical researcher Julie Ledgerwood said February 6 in Washington, D.C., at an American Society for Microbiology meeting on biothreats. The virus made headlines last year as it continued its tear through the Americas, and scientists confirmed its link to birth defects, including microcephaly (SN: 12/24/16, p. 19). Ledgerwood hopes to see efficacy data on the vaccine by the end of 2018.

“Ultimately, we want a vaccine that can prevent congenital Zika infection,” she said. “We think the DNA vaccine platform is an opportunity to do things safely and very quickly.”

Government researchers aren’t betting everything on DNA, though, Fauci points out. “We’ve got multiple shots on goal here,” he says. A slew of other vaccine candidates, based on both traditional and new techniques, are also in the works. But the DNA vaccine has stepped up to the plate first, and the world will soon see if it can deliver.

“If it works,” Durbin says, “we’ve hit a home run.”

Making a DNA vaccine is simple, in principle. Scientists synthesize genes from a pathogen, insert them into a circular strand of DNA called a plasmid, make lots of copies and then inject the purified plasmid into a person. “You can literally build a DNA vaccine in weeks,” says Dan Barouch, an immunologist at Beth Israel Deaconess Medical Center and Harvard Medical School. The approach is flexible, too, he adds. Researchers can tinker with the DNA building blocks in the plasmid, adding bits from other viruses that might ultimately enhance the immune response.

Story continues after graphic

Immune trigger

For a DNA vaccine against Zika, scientists insert genes for Zika proteins into a circular piece of DNA called a plasmid. Many copies of the plasmid are injected into muscle. Some of the DNA travels into cells’ nuclei, where it is used to make messenger RNA. After exiting the nucleus, mRNA helps build Zika proteins, which can form viruslike particles that trigger the immune system to make antibodies.

Zika DNA vaccine process

Barouch’s team was the first to report a Zika DNA vaccine that offered protection in mice — in a study published last June in Nature. Five weeks later, he and colleagues reported in Science that the vaccine, and two others created via different strategies, worked well in monkeys, too. And in September, a team led by government scientists, and including Barouch as a coauthor, came out with two additional DNA vaccine candidates, described in Science.

It’s one of those additional candidates, called VRC 5283, that the infectious diseases institute plans to test in…

Bacteria’s amyloids display surprising structure

 amyloid-like clumps made by bacteria
PROTEIN POWER Proteins from Staphylococcus aureus bacteria make amyloid-like clumps (the streamerlike structures in this illustration) that are toxic to human cells.

Clusters of a toxic bacterial protein have a surprising structure, differing from similar clumps associated with Alzheimer’s and Parkinson’s in humans, scientists report in the Feb. 24 Science.

These clusters, called amyloids, are defined in part by their structure: straight regions of protein chains called beta strands, folded accordion-style into flat beta sheets, which then stack up to form a fiber. That definition might now need to be broadened.

“All the amyloids that have been structurally looked at so far have certain characteristics,” says Matthew Chapman, a biologist at the University of Michigan in Ann Arbor who wasn’t part of the work. “This is the odd amyloid out right now.”

In the human brain, misfolded proteins can form amyloids that trigger neurodegenerative diseases. But amyloids aren’t always a sign of something gone wrong — some bacteria make amyloids to help defend their turf.

In Staphylococcus aureus, for example, the PSMα3 protein assembles into amyloids that help the bacteria kill other cells. Previous…

New imaging technique catches DNA ‘blinking’ on

fluorescing dna
LIGHTING UP When stimulated with light, DNA “blinks” on, making cellular structures (chromosome shown) visible without the need for fluorescent dyes.

BOSTON — A new imaging technique takes advantage of DNA’s natural ability to “blink” in response to stimulating light. The new approach will allow unprecedented views of genetic material and other cellular players. It’s the first method to resolve features smaller than 10 nanometers, biomedical engineer Vadim Backman said February 17 at the annual meeting of the American Association for the Advancement of Science.

DNA and proteins don’t naturally give off light, conventional wisdom holds, so scientists have developed fluorescent dyes…

Avoid the Harmful Effects of Dietary Lectins

The internet is ripe with foods we should or shouldn’t eat such as fat, sugar and salt. However there are properties in food that has not received as much attention. These are dietary lectins.

What are lectins? Lectins are proteins found in some foods that can have harmful effects on our body. They cannot be digested and end up in our bloodstream resulting in symptoms such as diarrhea, nausea and vomiting. These are the signs of food poisoning.

There are ways to protect ourselves. It starts with understanding which foods contain…