Peptide Bond

peptide bond

[′pep‚tīd ‚bänd] (organic chemistry) A bond in which the carboxyl group of one amino acid is condensed with the amino group of another to form a ‒CO·NH‒ linkage. Also known as peptide linkage.

Peptide Bond

(also peptide linkage), an amide bond that arises during the formation of proteins and peptides when the α-amino group (—NH₂) of one amino acid interacts with the α-carboxyl group (—COOH) of another amino acid:

where R₁ and R₂ are molecular parts that differ from one amino acid to another. The —CO—NH— group in proteins exhibits a keto-enol tautomerism.

The presence of peptide bonds in proteins and peptides was first proposed by A. Ia. Danilevskii and E. Fischer and later confirmed by chemical and physical data. Owing to tautomerism, the peptide bond exhibits a partial (40-percent) similarity to the double (conjugate) bond, which is indicated by the shorter length (1.32 A) of the peptide bond than of the single —C—N— bond (1.47 Å). The partially conjugate nature of the —C—N— bond determines the flat configuration of the —CO—NH— group (all four atoms are coplanar) and the existence of the trans and cis forms:

The greater stability of the trans form has been proved experimentally.

The enzymatic formation of peptide bonds in living cells occurs during protein biosynthesis. Laboratory methods have been developed for the chemical and enzymatic synthesis and cleavage of peptide bonds, thereby making it possible to synthesize a number of biologically active peptides and to determine the amino-acid sequence for many proteins and peptides.

N. N. ZAITSEVA

peptide bond

bond

[bond] the linkage between atoms or radicals of a chemical compound, or the symbol representing this linkage and indicating the number and attachment of the valencies of an atom in constitutional formulas, represented by a pair of dots or a line between atoms, e.g., H—O—H, H—C≡C—H or H:O:H, H:C:::C:H.coordinate covalent bond a covalent bond in which one of the bonded atoms furnishes both of the shared electrons.covalent bond a chemical bond between two atoms or radicals formed by the sharing of a pair (single bond), two pairs (double bond), or three pairs of electrons (triple bond).disulfide bond a strong covalent bond, —S—S—, important in linking polypeptide chains in proteins, the linkage arising as a result of the oxidation of the sulfhydryl (SH) groups of two molecules of cysteine.high-energy phosphate bond an energy-rich phosphate linkage present in adenosine triphosphate (ATP), phosphocreatine, and certain other biological molecules. On hydrolysis at pH 7 it yields about 8000 calories per mole, in contrast to the 3000 calories yielded by phosphate esters. The bond stores energy that is used to drive biochemical processes, such as the synthesis of macromolecules, contraction of muscles, and the production of the electrical potentials for nerve conduction.high-energy sulfur bond an energy-rich sulfur linkage, the most important of which occurs in the acetyl-CoA molecule, the main source of energy in fatty acid biosynthesis.hydrogen bond a weak, primarily electrostatic, bond between a hydrogen atom bound to a highly electronegative element (such as oxygen or nitrogen) in a given molecule, or part of a molecule, and a second highly electronegative atom in another molecule or in a different part of the same molecule.ionic bond a chemical bond in which electrons are transferred from one atom to another so that one bears a positive and the other a negative charge, the attraction between these opposite charges forming the bond.peptide bond the —CO—NH— linkage formed between the carboxyl group of one amino acid and the amino group of another; it is an amide linkage joining amino acids to form peptides.

pep·tide bond

the common link (-CO-NH-) between amino acids in proteins, actually a substituted amide, formed by elimination of H₂O between the -COOH of one amino acid and the H₂N- of another. Compare: eupeptide bond, isopeptide bond.

peptide bond

n. The chemical bond between carboxyl groups and amino groups of neighboring amino acids, forming an amide group and constituting the primary linkage of all protein structures.

pep·tide bond

(pep'tīd bond) The common link (-CO-NH-) between amino acids in proteins, formed by elimination of H₂O between the -COOH of one amino acid and the H₂N- of another.

peptide bond

A covalent bond formed between amino acids during protein synthesis. The OH- on a carbon atom links with the H- on a nitrogen atom to form a water molecule which is given off as each peptide bond is formed. Amino acids linked by peptide bonds form dipeptides, tripeptides or polypeptides.

Fig. 249 Peptide bond . Molecular structure. R₁ R₂ distinctive side-chains for different amino acids.

peptide bond

a covalent C arbon-N itrogen bond that joins the carboxyl group of one AMINO ACID to the amino group of another (with loss of a water molecule). See Fig. 249 . Many amino acids are joined by peptide bonds to form a POLYPEPTIDE CHAIN.

pep·tide bond

(pep'tīd bond) The common link (-CO-NH-) between amino acids in proteins.

peptide bond

peptide bond

peptide bond

Peptide Bond

peptide bond

Peptide Bond

peptide bond

bond

pep·tide bond

peptide bond

pep·tide bond

peptide bond

peptide bond

pep·tide bond

peptide bond

Synonyms for peptide bond

noun the primary linkage of all protein structures

Synonyms

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