Oncology & Cancer

New way to target cancer's diversity and evolution

Scientists have revealed close-up details of a vital molecule involved in the mix and match of genetic information within cells—opening up the potential to target proteins of this family to combat cancer's diversity and ...

Diseases, Conditions, Syndromes

Talking receptors may affect relaxin at work

Fibrosis, the damaging build-up of hardened or scarred tissue in the body, is a hallmark of various diseases and can lead to the dysfunction and failure of organs such as the heart and kidney. Fibrosis-related diseases in ...

Diabetes

Researchers identify trigger and mechanism in type 1 diabetes

Researchers at National Jewish Health have identified an elusive trigger of type 1 diabetes. A protein fragment formed in the pancreas activates the immune system's T cells, leading them to attack and destroy beta cells, ...

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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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