Peptide synthesis: Difference between revisions
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= Peptide Synthesis = | |||
[[File:Peptide_coupling.svg|thumb|right|300px|General scheme of peptide coupling.]] | |||
'''Peptide synthesis''' is the process of creating [[peptides]], which are short chains of [[amino acids]] linked by [[peptide bonds]]. This process is fundamental in the field of [[biochemistry]] and [[molecular biology]], as peptides play crucial roles in biological functions and are used in research and therapeutic applications. | |||
== Methods == | == Methods of Peptide Synthesis == | ||
Peptide synthesis can be performed using various methods, each with its own advantages and limitations. The two primary methods are [[liquid-phase peptide synthesis]] and [[solid-phase peptide synthesis]]. | |||
=== Liquid-Phase Peptide Synthesis === | |||
Liquid-phase peptide synthesis involves the sequential addition of amino acids in solution. This method was historically significant but has largely been replaced by solid-phase techniques due to the latter's efficiency and ease of purification. | |||
=== Solid-Phase Peptide Synthesis === | === Solid-Phase Peptide Synthesis === | ||
SPPS, | [[File:Solid_Phase_Peptide_Synthesis.jpg|thumb|left|300px|Solid-phase peptide synthesis apparatus.]] | ||
Solid-phase peptide synthesis (SPPS) is the most common method used today. It involves anchoring the C-terminal amino acid of the peptide to an insoluble resin, allowing for the sequential addition of protected amino acids. This method was pioneered by [[Robert Bruce Merrifield]], who was awarded the [[Nobel Prize in Chemistry]] in 1984 for this innovation. | |||
== Coupling Reagents == | |||
The formation of peptide bonds requires activation of the carboxyl group of the incoming amino acid. Various coupling reagents are used to facilitate this process. | |||
=== Carbodiimide Reagents === | |||
[[File:DIC_HOBt_coupling.svg|thumb|right|300px|DIC/HOBt coupling mechanism.]] | |||
Carbodiimides, such as [[dicyclohexylcarbodiimide]] (DCC) and [[diisopropylcarbodiimide]] (DIC), are commonly used in peptide synthesis. They activate the carboxyl group to form an active ester, which then reacts with the amine group of the next amino acid. | |||
=== Additives === | |||
[[File:HOBT.png|thumb|left|150px|Structure of HOBt.]] | |||
Additives such as [[1-hydroxybenzotriazole]] (HOBt) and [[1-hydroxy-7-azabenzotriazole]] (HOAt) are often used to suppress racemization and improve yields. | |||
[[File:1-hydroxy-7-aza-benzotriazole.svg|thumb|right|150px|Structure of HOAt.]] | |||
== Protecting Groups == | |||
Protecting groups are essential in peptide synthesis to prevent unwanted side reactions. The most common protecting groups are used for the N-terminus and side chains of amino acids. | |||
=== N-Terminus Protecting Groups === | |||
=== | [[File:Cbz_to_protect_N-terminus.svg|thumb|left|300px|Cbz protecting group for N-terminus.]] | ||
The [[carbobenzyloxy]] (Cbz), [[tert-butyloxycarbonyl]] (Boc), and [[9-fluorenylmethyloxycarbonyl]] (Fmoc) groups are commonly used to protect the N-terminus of amino acids. | |||
=== Side Chain Protecting Groups === | |||
Side chain protecting groups are used to protect functional groups on the amino acid side chains that might react during peptide synthesis. | |||
== Deprotection == | |||
After the peptide chain is assembled, the protecting groups must be removed to yield the final peptide. | |||
=== Boc Deprotection === | |||
[[File:Boc_deprotection_peptide.svg|thumb|right|300px|Boc deprotection mechanism.]] | |||
Boc groups are removed using strong acids such as [[trifluoroacetic acid]] (TFA). | |||
== | === Fmoc Deprotection === | ||
[[File:Fmoc-PG_Cleavage.png|thumb|left|300px|Fmoc deprotection mechanism.]] | |||
Fmoc groups are removed using mild bases such as [[piperidine]]. | |||
== Related Pages == | |||
* [[Amino acid synthesis]] | |||
* [[Protein biosynthesis]] | |||
* [[Biochemistry]] | |||
[[Category: | [[Category:Peptide synthesis]] | ||
Latest revision as of 14:18, 21 February 2025
Peptide Synthesis[edit]
Peptide synthesis is the process of creating peptides, which are short chains of amino acids linked by peptide bonds. This process is fundamental in the field of biochemistry and molecular biology, as peptides play crucial roles in biological functions and are used in research and therapeutic applications.
Methods of Peptide Synthesis[edit]
Peptide synthesis can be performed using various methods, each with its own advantages and limitations. The two primary methods are liquid-phase peptide synthesis and solid-phase peptide synthesis.
Liquid-Phase Peptide Synthesis[edit]
Liquid-phase peptide synthesis involves the sequential addition of amino acids in solution. This method was historically significant but has largely been replaced by solid-phase techniques due to the latter's efficiency and ease of purification.
Solid-Phase Peptide Synthesis[edit]
Solid-phase peptide synthesis (SPPS) is the most common method used today. It involves anchoring the C-terminal amino acid of the peptide to an insoluble resin, allowing for the sequential addition of protected amino acids. This method was pioneered by Robert Bruce Merrifield, who was awarded the Nobel Prize in Chemistry in 1984 for this innovation.
Coupling Reagents[edit]
The formation of peptide bonds requires activation of the carboxyl group of the incoming amino acid. Various coupling reagents are used to facilitate this process.
Carbodiimide Reagents[edit]
Carbodiimides, such as dicyclohexylcarbodiimide (DCC) and diisopropylcarbodiimide (DIC), are commonly used in peptide synthesis. They activate the carboxyl group to form an active ester, which then reacts with the amine group of the next amino acid.
Additives[edit]
Additives such as 1-hydroxybenzotriazole (HOBt) and 1-hydroxy-7-azabenzotriazole (HOAt) are often used to suppress racemization and improve yields.
Protecting Groups[edit]
Protecting groups are essential in peptide synthesis to prevent unwanted side reactions. The most common protecting groups are used for the N-terminus and side chains of amino acids.
N-Terminus Protecting Groups[edit]
The carbobenzyloxy (Cbz), tert-butyloxycarbonyl (Boc), and 9-fluorenylmethyloxycarbonyl (Fmoc) groups are commonly used to protect the N-terminus of amino acids.
Side Chain Protecting Groups[edit]
Side chain protecting groups are used to protect functional groups on the amino acid side chains that might react during peptide synthesis.
Deprotection[edit]
After the peptide chain is assembled, the protecting groups must be removed to yield the final peptide.
Boc Deprotection[edit]
Boc groups are removed using strong acids such as trifluoroacetic acid (TFA).
Fmoc Deprotection[edit]
Fmoc groups are removed using mild bases such as piperidine.
