Editing Peptide synthesis (section)

{{Short description|Production of peptides}}
{{Use dmy dates|date=February 2023}}
[[File:Peptide coupling.svg|thumb|right|Coupling of two [[amino acid]]s in solution. The unprotected amine of one reacts with the unprotected carboxylic acid group of the other to form a [[peptide bond]]. In this example, the second reactive group (amine/acid) in each of the starting materials bears a [[protecting group]].]]

In [[organic chemistry]], '''peptide synthesis''' is the production of [[peptide]]s, compounds where multiple [[amino acid]]s are linked via amide bonds, also known as [[peptide bond]]s. Peptides are chemically synthesized by the condensation reaction of the [[carboxyl group]] of one amino acid to the [[amine group|amino group]] of another. [[Protecting group]] strategies are usually necessary to prevent undesirable side reactions with the various amino acid side chains.<ref name="Isidro-Llobet09">{{cite journal | vauthors = Isidro-Llobet A, Alvarez M, Albericio F | title = Amino acid-protecting groups | journal = Chemical Reviews | volume = 109 | issue = 6 | pages = 2455–2504 | date = June 2009 | pmid = 19364121 | doi = 10.1021/cr800323s | ref = Isidro-Llobet09 | hdl-access = free | hdl = 2445/69570 | s2cid = 90409290 }}</ref> Chemical peptide synthesis most commonly starts at the carboxyl end of the peptide (C-terminus), and proceeds toward the amino-terminus ([[N-terminus]]).<ref name="chan00">{{cite book| vauthors = Chan WC, White PD |title=Fmoc Solid Phase Peptide Synthesis: A Practical Approach|date=2000|publisher=OUP|location=Oxford, UK|isbn=978-0-19-963724-9}}</ref> [[Protein biosynthesis]] (long peptides) in living organisms occurs in the opposite direction.

The chemical synthesis of peptides can be carried out using classical solution-phase techniques, although these have been replaced in most research and development settings by solid-phase methods (see below).<ref name=":3">{{cite journal | vauthors = Jaradat DM | title = Thirteen decades of peptide synthesis: key developments in solid phase peptide synthesis and amide bond formation utilized in peptide ligation | journal = Amino Acids | volume = 50 | issue = 1 | pages = 39–68 | date = January 2018 | pmid = 29185032 | doi = 10.1007/s00726-017-2516-0 | s2cid = 3680612 }}</ref> Solution-phase synthesis retains its usefulness in large-scale production of peptides for industrial purposes moreover.

Although [[Protein production|recombinant protein]] is more cost effective for large-scale production,<ref>{{cite web |date=April 7, 2024 |title=Next generation peptide drugs favor synthetic, not recombinant manufacturing |url=https://www.bachem.com/articles/commercial-apis/next-generation-peptide-drugs-favor-synthetic-not-recombinant-manufacturing/ |website=Bachem |access-date=March 13, 2025}}</ref> chemical synthesis facilitates the production of peptides that are difficult to [[Protein production|express]] in bacteria, the incorporation of unnatural amino acids, peptide/protein backbone modification, and the synthesis of D-proteins, which consist of [[Amino acid#Chirality|D-amino acids]].