C-terminal amides mark proteins for degradation via SCF/FBXO31 The C-terminal amidation of peptides is a crucial post-translational modification that significantly impacts their biological activity, stability, and function.C-Terminus - an overview | ScienceDirect Topics This process involves converting the terminal carboxyl group (-COOH) of a peptide into an amide group (-CONH2).2020年6月20日—Amidationis one of the most common post-translational modification in which theC-terminalcarboxyl group is replaced by an amide group. This seemingly small chemical change can profoundly alter a peptide's properties, making it a vital modification in areas ranging from natural peptide hormone biosynthesis to the development of therapeutic peptides. Understanding the mechanisms, applications, and implications of C-terminal amidation is key for researchers and scientists working with peptides.
C-terminal amidation plays a critical role in the biological activity of a vast number of peptides, with estimates suggesting that over 50% of known peptide hormones are amidated.C-terminal amidationcan reduce the overall charge of the peptide, but may reduce the solubility of the peptide. End blocking of the peptide brings it closer to ... This modification is often essential for a peptide to exert its full physiological effectHow do you designate peptide modifications, e.g. a C- .... For instance, C-terminal amidation can neutralize the negative charge typically present at the C-terminus, which can enhance receptor binding and improve interaction with biological targets. This charge neutralization also contributes to increased stability by protecting the peptide from exopeptidases, enzymes that degrade peptides from the C-terminus. Consequently, amidated peptides often exhibit longer half-lives in biological systems.Process for the conversion of C-terminal peptide esters or ...
Beyond receptor binding and stability, C-terminal amidation can influence other critical peptide characteristics.作者：E Logerot·2022·被引用次数：6—As such,C-terminal amidation is a post-translational modificationthat can be considered as a signature of bioactivity since the majority of known amidated ... It can affect the peptide's secondary structure, promoting specific conformations like helical structures that are important for function, as observed in membrane-disrupting antimicrobial peptides (AMPs). The modification can also impact how peptides interact with lipid bilayers and influence their overall pharmacokinetic profile.
The production of C-terminally amidated peptides can occur through various pathways, broadly categorized into biological (post-translational) and chemical methods.
1. Biological Amidation:
In living organisms, C-terminal amidation is a common post-translational modification that occurs after the initial synthesis of a peptide precursor.C‐Terminal Peptide Amidation Catalyzed by Orange ... This process typically involves a two-step enzymatic reaction:
* Peptide cleavage: A precursor peptide, often with a C-terminal glycine extension, is cleaved by a peptidylglycine alpha-amidating monooxygenase (PAM) enzyme.
* Amidation: The PAM enzyme then catalyzes the oxidation and amidation of the newly formed C-terminal residue, converting the carboxyl group into an amide. This process requires molecular oxygen, ascorbate (Vitamin C), and copper ions.
This enzymatic pathway is highly specific and is a final, essential step in the biosynthesis of many bioactive peptides, including peptide hormones and neurotransmitters. Recent advancements have also explored the use of plant ligase enzymes for in vitro production of C-terminally amidated peptides from unprotected carboxylate precursorsComprehensive Guide to Peptide C-Terminal Modifications.
2. Chemical Amidation:
For research purposes, therapeutic development, or when biological systems are not feasible, chemical methods are employed to achieve C-terminal amidation. These methods offer flexibility and scalability. Common chemical approaches include:
* Direct amidation of amino acids and peptides: Reactions involving amino acids or peptides with isocyanates, often catalyzed by reagents like DMAP (4-dimethylaminopyridine), can lead to C-terminal or side-chain amidation作者：E Logerot·2022·被引用次数：6—As such,C-terminal amidation is a post-translational modificationthat can be considered as a signature of bioactivity since the majority of known amidated ....
* Amidation of C-terminal esters or acids: This involves converting peptide esters or acids into amides, often using reagents like ammonium chloride (NH4Cl), alkylammonium chlorides, or semicarbazide hydrochloride. Various coupling reagents like EDC.HCl, DIC, HATU, HBTU, and TBTU, along with additives like HOBt and DMAP, are frequently used in solution-phase synthesis to facilitate these reactions.
* Photochemical approaches: Novel methods are emerging, such as photochemically-enabled production, which allows for the C-terminal α-amidation of peptides and proteins from cysteine-extended polypeptide precursors.
The choice of chemical method depends on factors such as the peptide sequence, desired yield, purity requirements, and available reagentsThis work explores theproduction of C-terminally amidated peptidesfrom unprotected carboxylate precursors using a plant ligase enzyme.. Some methods aim for "one-pot" syntheses, increasing efficiency and sustainability.
The impact of C-terminal amidation extends across various scientific disciplines and practical applications:
* Therapeutic Peptides: Amidation is extensively used in the design and synthesis of therapeutic peptides. By enhancing biological activity, improving stability, and prolonging half-life, amidation can significantly improve the efficacy and delivery of peptide-based drugs. Examples include certain antimicrobial peptides (AMPs) and peptide hormones where the amidated form is crucial for their intended therapeutic effectThe effect of amidation on the behaviour of antimicrobial ....
* Biomarkers and Signaling Molecules: Many endogenous peptides that act as hormones, neurotransmitters, or signaling molecules rely on C-terminal amidation for their functionC-terminal amidated peptides: production by the in vitro .... For example, neuropeptide Y (NPY) requires amidation to become biologically activeAmidation - an overview | ScienceDirect Topics.
* Antimicrobial Peptides (AMPs): A significant proportion of naturally occurring AMPs are C-terminally amidated. This modification is often essential for their membrane-disrupting activity and their ability to combat bacterial infections.
* Research Tools: Amidating peptides chemically or enzymatically provides researchers with valuable tools to study structure-activity relationships, understand peptide-receptor interactions, and investigate the role of amidation in various biological processes作者：IF Eggen·2008·被引用次数：2—The present invention relates to a process for theamidation of C-terminal estersor acids of peptide substrates in solution-phase synthesis ....
While beneficial, C-terminal amidation also presents considerations:
* Solubility: In some cases, amidation can reduce the overall solubility of a peptide due to the loss of a charged group.
* Synthesis Complexity: Chemical amidation can sometimes be challenging, requiring careful optimization of reaction conditions and purification steps to achieve high yields and purity, especially for complex peptide sequences.
* Cost: Enzymatic or complex chemical synthesis routes can add to the production cost of amidated peptides作者：H Li·2023·被引用次数：2—In this study, we present a series ofsmall-molecule C-terminal amidation tagsbased on phosphonate or aliphatic moieties..
Despite these challenges, the indispensable role of C-terminal amidation in peptide biology ensures its continued importance in research and the development of novel peptide-based therapeutics and tools. The ongoing development of more efficient and sustainable synthetic and enzymatic methods promises to further expand the accessibility and application of C-terminally amidated peptides作者：V Čeřovský·1998·被引用次数：30—The C-terminal carboxy group of the peptide is directly converted into an amide groupby condensation with an ammonium salt. The amidation of ....
Join the newsletter to receive news, updates, new products and freebies in your inbox.