Polypeptide self-assembly directed by the addition of cosolvents

Very different nanostructures are formed through the self-assembly of a polypeptide depending on which of two cosolvents is added to the reaction mixture, three RIKEN chemists have shown. This discovery is of fundamental ...

Exploring tiny forces with single molecule force spectroscopy

In terms of space organization, DNA has powers rivaling Marie Kondo. A strand of DNA that is two meters long intricately folds itself into a cell nucleus only 10 microns across. (One of the hairs on your head has a diameter ...

Major advance in nanopore detection of peptides and proteins

Nanopore technology, which is used to sequence DNA, is cheap, hand-held and works in the jungle and in space. The use of this technology to identify peptides or proteins is now a step closer. University of Groningen scientists ...

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Peptides (from the Greek πεπτός, "digested" from πέσσειν "to digest") are short polymers of amino acid monomers linked by peptide bonds. They are distinguished from proteins on the basis of size, typically containing less than 50 monomer units. The shortest peptides are dipeptides, consisting of two amino acids joined by a single peptide bond. There are also tripeptides, tetrapeptides, etc. Amino acids which have been incorporated into a peptide are termed "residues"; every peptide has a N-terminus and C-terminus residue on the ends of the peptide (except for cyclic peptides). A polypeptide is a long, continuous, and unbranched peptide. Proteins consist of one or more polypeptides arranged in a biologically functional way and are often bound to cofactors, or other proteins.

The size boundaries which distinguish peptides, polypeptides, and proteins are arbitrary. Long peptides such as amyloid beta can be considered proteins, whereas small proteins such as insulin can be considered peptides.

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