Peptide

Peptide

Peptides (from the Greek πεπτός, "digested" from πέσσειν "to digest") are short polymers of amino acid monomers linked by peptide bonds, the covalent chemical bonds formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule. Peptides are distinguished from proteins on the basis of size, typically containing fewer 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 that 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.

Read more about Peptide:  Peptide Classes, Peptides in Molecular Biology, Well-known Peptide Families in Humans, Notes On Terminology

Other articles related to "peptides, peptide":

Biopanning
... is an affinity selection technique which selects for peptides that bind to a given target ... All peptide sequences obtained from biopanning using combinatorial peptide libraries have been stored in a special database with the name MimoDB ... Biopanning involves 4 major steps for peptide selection ...
Selected Reaction Monitoring - SRM in Proteomics
... ionization in an electrospray source, a peptide precursor is first isolated to obtain a substantial ion population of mostly the intended species ... are indicative of the abundance of the peptide in the sample ... D, 13C, or 15N) peptides to a complex matrix as concentration standards, SRM can be used to construct a calibration curve that can provide the absolute ...
Peptide - Notes On Terminology
... An oligopeptide (or simply a peptide) is a polypeptide less than 30-50 amino acids long ... multiplier Function A neuropeptide is a peptide that is active in association with neural tissue ... A lipopeptide is a peptide that has a lipid connected to it, and pepducins are lipopeptides that interact with GPCRs ...
List Of Human Hormones - Peptide
... vasoconstriction Release ACTH in anterior pituitary Atrial-natriuretic peptide (or atriopeptin) ANP heart ANP receptor → cGMP Brain natriuretic peptide BNP ... secretin, motilin, vasoactive intestinal peptide (VIP), gastric inhibitory polypeptide (GIP), enteroglucagon in gastrointestinal system Lowers rate of gastric emptying Reduces smooth muscle ...
Label-free Quantification - Detecting Peptides
... Typically, peptide signals are detected at the MS1 level and distinguished from chemical noise through their characteristic isotopic pattern ... and used to reconstruct a chromatographic elution profile of the mono-isotopic peptide mass ... The total ion current of the peptide signal is then integrated and used as a quantitative measurement of the original peptide concentration ...