News tagged with protein

Related topics: cells · genes · cancer · cancer cells · amino acids

Aggressive cancer cells halted

Zebrafish-human communication shows that cancer cells lacking a signaling protein are less able to develop aggressive metastatic properties. This discovery has been made by Claudia Tulotta. PhD defence 14 June.

Jun 10, 2016
popularity15 comments 0

Proteome of an entire family

Scientists have won new knowledge on the molecular background of fat and energy metabolism disorders through a large-scale proteomic study with mice. The proteome is the entire set of proteins - in this case, proteins from ...

Jun 09, 2016
popularity35 comments 0

Cancer researchers take on an old foe

In the annals of cancer research, a protein known as KRas has become notorious. Part of a family of proteins implicated in 30 percent of cancers, KRas is considered a highly desirable but defiant drug target. Scientists have ...

Jun 08, 2016
popularity2 comments 0

Biomarkers from microvesicles

Alicia Llorente is the project leader for the project "Microvesicles as a Source of Prostate Cancer Biomarkers". Alicia works as a project group leader at the Department of Molecular Cell Biology, Institute for Cancer Research ...

Jun 08, 2016
popularity0 comments 0

How diabetes disrupts the immune system

New findings into how type 1 diabetes disrupts the immune system and impacts a person's risk of developing the condition have been uncovered by a team of researchers from the Harry Perkins Institute of Medical Research – ...

Jun 03, 2016
popularity23 comments 0

Protein

Proteins (also known as polypeptides) are organic compounds made of amino acids arranged in a linear chain. The amino acids in a polymer chain are joined together by the peptide bonds between the carboxyl and amino groups of adjacent amino acid residues. The sequence of amino acids in a protein is defined by the sequence of a gene, which is encoded in the genetic code. In general, the genetic code specifies 20 standard amino acids, however in certain organisms the genetic code can include selenocysteine — and in certain archaea — pyrrolysine. Shortly after or even during synthesis, the residues in a protein are often chemically modified by post-translational modification, which alter the physical and chemical properties, folding, stability, activity, and ultimately, the function of the proteins. Proteins can also work together to achieve a particular function, and they often associate to form stable complexes.

Like other biological macromolecules such as polysaccharides and nucleic acids, proteins are essential parts of organisms and participate in virtually every process within cells. Many proteins are enzymes that catalyze biochemical reactions and are vital to metabolism. Proteins also have structural or mechanical functions, such as actin and myosin in muscle and the proteins in the cytoskeleton, which form a system of scaffolding that maintains cell shape. Other proteins are important in cell signaling, immune responses, cell adhesion, and the cell cycle. Proteins are also necessary in animals' diets, since animals cannot synthesize all the amino acids they need and must obtain essential amino acids from food. Through the process of digestion, animals break down ingested protein into free amino acids that are then used in metabolism.

Proteins were first described and named by the Swedish chemist Jöns Jakob Berzelius in 1838. However, the central role of proteins in living organisms was not fully appreciated until 1926, when James B. Sumner showed that the enzyme urease was a protein. The first protein to be sequenced was insulin, by Frederick Sanger, who won the Nobel Prize for this achievement in 1958. The first protein structures to be solved were hemoglobin and myoglobin, by Max Perutz and Sir John Cowdery Kendrew, respectively, in 1958. The three-dimensional structures of both proteins were first determined by x-ray diffraction analysis; Perutz and Kendrew shared the 1962 Nobel Prize in Chemistry for these discoveries. Proteins may be purified from other cellular components using a variety of techniques such as ultracentrifugation, precipitation, electrophoresis, and chromatography; the advent of genetic engineering has made possible a number of methods to facilitate purification. Methods commonly used to study protein structure and function include immunohistochemistry, site-directed mutagenesis, and mass spectrometry.

This text uses material from Wikipedia, licensed under CC BY-SA

Subscribe to rss feed