Peptide bond

Peptide bond is a chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule, releasing a molecule of water (H2O). This is a dehydration synthesis reaction (also known as a condensation reaction), and it is the process by which the primary structure of all proteins is formed.

Formation

The formation of a peptide bond requires energy, which is derived from ATP. The reaction is a condensation reaction, meaning that water is produced during the reaction. The formation of a peptide bond is a slow reaction in the absence of a catalyst, but it is sped up by the ribosome during protein synthesis.

Structure

The peptide bond is a resonance hybrid of two canonical forms, which contributes to its stability. The bond is shorter than a single bond, but longer than a double bond. This partial double bond character restricts rotation around the peptide bond, which helps to define the shape of proteins.

Properties

Peptide bonds are amide type of covalent chemical bonds formed by the condensation of one amino group of one amino acid and the carboxyl group of another amino acid. Peptide bonds are very stable, having a lifetime of 7 years in neutral water solution.

Hydrolysis

Peptide bonds can be broken by hydrolysis, which is the reverse of the condensation reaction that forms them. This reaction is extremely slow in the absence of a catalyst. Enzymes that catalyze the hydrolysis of peptide bonds are known as proteases.

See also

• Protein structure
• Amino acid
• Protein biosynthesis
• Protease

Peptide_bond

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  Peptide bond
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  Peptide formation ball model
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  Amino acid condensation
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  Cis-trans isomerization kinetics of X-Pro peptide bonds