Tag: Proteins

More Than 25 Years of Competition and Collaboration Advance the Prediction of Protein Shapes


Proteins (such as hemoglobin, actin, and amylase) are workhorse molecules that contribute to virtually every activity in the body. Some of proteins’ many jobs include carrying oxygen from your lungs to the rest of your body (hemoglobin), allowing your muscles to move (actin and myosin), and digesting your food (amylase, pepsin, and lactase). All proteins are made up of chains of amino acids that fold into specific 3D structures, and each protein’s structure allows it to perform its distinct job. Proteins that are misfolded or misshapen can cause diseases such as Parkinson’s or cataracts.

While it’s straightforward to use the genetic code to predict amino acid sequences of proteins from gene sequences, the vast diversity of protein shapes and many factors that influence a protein’s 3D structure make it much more complicated to create simple folding rules that could be used to predict proteins’ structures from these sequences. Scientists have worked on this problem for nearly 50 years, and NIGMS has supported many of their efforts, including the Critical Assessment of Structure Prediction (CASP) program.

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Dairy Deconstructor: How an Enzyme Enables Milk Digestion


Did you know that the lack of a single enzyme is responsible for lactose intolerance, a common condition that causes people to have trouble digesting milk? Fortunately, the enzyme is available in an over-the-counter pill for lactose-intolerant people who want to enjoy dairy products. Enzymes are molecules—almost always proteins—that speed up chemical reactions by reducing the amount of energy needed for the reactions to proceed. Without them, many processes in our bodies would essentially grind to a halt.

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Pumping Iron: The Heavy Lifting Iron Does in Our Bodies


Our blood appears red for the same reason the planet Mars does: iron. The element may bring to mind cast-iron pans, wrought-iron fences, or ancient iron tools, but it’s also essential to life on Earth. All living organisms, from humans to bacteria, need iron. It’s crucial for many processes in the human body, including oxygen transport, muscle function, proper growth, cell health, and the production of several hormones.

A graphic showing iron’s abbreviation, atomic number, and atomic weight connected by lines to illustrations of a vial of blood, Mars, and Earth. Iron is the reason both our blood and the planet Mars appear red. The element also makes up the majority of Earth’s core and generates the planet’s magnetic field. Credit: Compound Interest. CC BY-NC-ND 4.0. Click to enlarge
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Quiz: Prove Your Knowledge of Proteins!


Proteins play a role in virtually every activity in the body. They make up hair and nails, help muscles move, protect against infection, and more. Many NIGMS-funded researchers study the rich variety of proteins in humans and other organisms to shed light on their roles in health and disease.

Take our quiz to test how much you know about proteins. Afterward, find more quizzes and other fun learning tools on our activities and multimedia webpage, which includes an interactive protein alphabet.

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Through the Looking Glass: Microscopic Structures in Many Sizes


We seldom see microscopic objects next to one another, so it can be difficult to picture how they compare. For instance, it might surprise you that a thousand cold-virus particles could line up across one human skin cell! The largest objects that scientists view through microscopes are about a millimeter (roughly the size of a poppyseed), and they’re about 10 million times larger than the smallest molecules scientists can view: atoms.

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An Enlightening Protein

A fly glowing green. A fruit fly expressing GFP. Credit: Jay Hirsh, University of Virginia.

During the holiday season, twinkling lights are a common sight. But no matter what time of the year, you can see colorful glows in many biology labs. Scientists have enabled many organisms to light up in the dark—from cells to fruit flies and Mexican salamanders. These glowing organisms help researchers better understand basic cell processes because their DNA has been edited to express molecules such as green fluorescent protein.

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PECASE Honoree Michael Boyce on Sugar’s Role in Cell Signaling and on Diversity, Equity, and Inclusion in the Scientific Workforce

Headshot of Michael Boyce. Michael Boyce, associate professor of biochemistry at Duke University in Durham, North Carolina. Credit: Michael Boyce.

Sugars aren’t merely energy sources for our cells. They also play important signaling roles through a process called glycosylation, where they attach to proteins and lipids as tags. Although these sugar tags, called glycans, impact many cellular processes, they have long been understudied due to technical challenges. Now, advances in analytical tools like mass spectrometry are enabling scientists to examine the enormous complexity of glycans. Other advances also allow researchers to synthesize complex sugars, providing them with standards for analytical experiments.

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RNA Polymerase: A Target for New Antibiotic Drugs?

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DNA, with its double-helix shape, is the stuff of genes. But genes themselves are only “recipes” for protein molecules, which are molecules that do the real heavy lifting (or do much of the work) inside cells.

RNAP illustrated as a crab claw, clamping on a DNA double helix. Artist interpretation of RNAP grasping and unwinding a DNA double helix. Credit: Wei Lin and Richard H. Ebright.

Here’s how it works. A molecular machine called RNA polymerase (RNAP) travels along DNA to find a place where a gene begins. RNAP uses a crab-claw-like structure to grasp and unwind the DNA double helix at that spot. RNAP then copies (“transcribes”) the gene into messenger RNA (mRNA), a molecule similar to DNA.

The mRNA molecule travels to one of the cell’s many protein-making factories (ribosomes), which use the mRNA message as instructions for making a specific protein.

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