Diseases, Conditions, Syndromes

Antibody neutralizes SARS and COVID-19 coronaviruses

An antibody first identified in a blood sample from a patient who recovered from Severe Acute Respiratory Syndrome in 2003 inhibits related coronaviruses, including the cause of COVID-19.

Diseases, Conditions, Syndromes

Nanobodies hold the key to imaging COVID-19

Researchers from Protein Production UK, a collaborative project led by The Rosalind Franklin Institute, have isolated nanobodies—a type of antibody used in research, which bind to the 'spike' protein of the SARS-CoV-2 virus.

Alzheimer's disease & dementia

New imaging method sheds light on Alzheimer's disease

To understand what happens in the brain when Alzheimer's disease develops, researchers need to be able to study the molecular structures in the neurons affected by Alzheimer's disease. Researchers at Lund University in Sweden ...

Diseases, Conditions, Syndromes

New drug target found for COVID-19

A new potential drug target has been identified in SARS CoV-2—the virus that causes COVID-19—by scientists at the Center of Structural Genomics of Infectious Diseases, or CSGID, who say multiple drugs will be needed to ...

Oncology & Cancer

How the immune system becomes blind to cancer cells

T cells play a huge role in our immune system's fight against modified cells in the body that can develop into cancer. Phagocytes and B cells identify changes in these cells and activate the T cells, which then start a full-blown ...

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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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