New 'radar' detects active cellular destroyers

Cells in the human body must adapt their protein balance to certain situations, such as the availability of iron or an infection. These adaptations occur through a complex process in which proteins that are no longer needed ...

Neural network helps design brand new proteins

With their intricate arrangements and dynamic functionalities, proteins perform a plethora of biological tasks by employing unique arrangements of simple building blocks where geometry is key. Translating this nearly limitless ...

Deciphering the molecular dynamics of complex proteins

Which structures do complex proteins adopt in solution? Konstanz biophysicists answer this question using the example of ubiquitin dimers as well as a new combination of high-resolution NMR spectroscopy and sophisticated ...

New inhibitor for regulating the essential protein SMNDC1

The SMNDC1 gene controls key functions in the human body and is linked to diseases such as diabetes and cancer. Scientists in Stefan Kubicek's research group at the CeMM Research Center for Molecular Medicine of the Austrian ...

Deep learning for new protein design

The key to understanding proteins—such as those that govern cancer, COVID-19, and other diseases—is quite simple: Identify their chemical structure and find which other proteins can bind to them. But there's a catch.

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Protein structure

Proteins are an important class of biological macromolecules present in all biological organisms, made up of such elements as carbon, hydrogen, nitrogen, oxygen, and sulphur. All proteins are polymers of amino acids. The polymers, also known as polypeptides, consist of a sequence of 20 different L-α-amino acids, also referred to as residues. For chains under 40 residues the term peptide is frequently used instead of protein. To be able to perform their biological function, proteins fold into one, or more, specific spatial conformations, driven by a number of noncovalent interactions such as hydrogen bonding, ionic interactions, Van Der Waals forces and hydrophobic packing. In order to understand the functions of proteins at a molecular level, it is often necessary to determine the three dimensional structure of proteins. This is the topic of the scientific field of structural biology, that employs techniques such as X-ray crystallography or NMR spectroscopy, to determine the structure of proteins.

A number of residues are necessary to perform a particular biochemical function, and around 40-50 residues appears to be the lower limit for a functional domain size. Protein sizes range from this lower limit to several thousand residues in multi-functional or structural proteins. However, the current estimate for the average protein length is around 300 residues. Very large aggregates can be formed from protein subunits, for example many thousand actin molecules assemble into a microfilament.

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