Cisprolinevs transproline The peptide bond with proline presents unique characteristics that significantly influence protein structure and function. Unlike other amino acids, proline's cyclic side chain affects peptide bond formation, conformation, and subsequent biological processes. Understanding these peculiarities is crucial for comprehending protein folding, stability, and the activity of proline-rich peptides.2017年10月21日—Apeptide bondis an amide type of covalent chemical bond linking two consecutive alpha-amino acids from C1 of one alpha-amino acid and N2 of another.
Proline is an amino acid that stands apart due to its cyclic structure, where the amino group is incorporated into the side chain, forming a secondary amine.作者：FX Schmid·1986·被引用次数：106—The isomerization of theproline peptide bondbetween tyrosine-92 and proline-93 in bovine pancreatic ribonuclease A has been investigated in the unfolded ... This structural feature has profound implications for the peptide bond it forms. When proline is part of a peptide chain, the bond formed at its C-terminus (the bond between the carboxyl group of proline and the amino group of the next amino acid) is unique. This secondary amine means proline lacks a hydrogen atom on its alpha-amino group, which prevents it from acting as a hydrogen bond donor in stabilizing secondary structures like alpha-helices or beta-sheetsStatistically significant dependence of the Xaa-Pro peptide ....
Furthermore, the peptide bond involving proline exhibits a higher propensity to exist in the *cis* conformation compared to peptide bonds involving other amino acids, which predominantly favor the *trans* conformationWhenprolineis in apeptide bond, it does not have a hydrogen on the α amino group, so it cannot donate a hydrogen bond to stabilize an α helix or a β sheet.. This *cis/trans* isomerization around the peptide bond is a slow process, especially when proline is involved, acting as a kinetic bottleneck in protein folding. This isomerization capability allows proline to introduce kinks and turns in peptide chains, conferring unique conformational constraints.Proline
The presence of proline significantly impacts the rate of peptide bond formation during protein synthesis.2026年1月10日—Proline, an amino acid obtained by hydrolysis of proteins. Its molecule contains a secondary amino group (>NH) rather than the primary amino ... Research indicates that proline incorporates into newly forming polypeptide chains at a considerably slower rate than many other amino acids. This slower incorporation can lead to ribosome stalling, a phenomenon that can be amplified in proteins rich in proline residues. This kinetic impediment is largely attributed to the unique chemical nature of the proline peptide bond and its associated isomerization.
The *cis/trans* isomerization of the proline peptide bond is a critical step in the folding pathways of many proteins. While other peptide bonds rapidly adopt their preferred *trans* conformation, the proline peptide bond's ability to exist in both states and its slow isomerization rate can delay the attainment of the native protein structureWhat is the reason for proline not having a peptide bond?. This characteristic is particularly pronounced in proline-rich signaling peptides and can influence the biological processing and activity of these molecules.
The *cis* and *trans* conformations of the proline peptide bond are not merely theoretical possibilities; they have tangible effects on peptide and protein structure. While the *trans* conformation is generally more stable for most amino acid peptide bonds, proline's cyclic structure allows it to readily adopt and stabilize the *cis* conformation作者：F Krieger·2005·被引用次数：309—Pseudo-proline (ΨPro) is known to increase the cis content of a Val-Pro peptide bond to about 80% due to steric effects induced by the methyl groups in the .... This ability to exist in both states contributes to proline's role as a "structure breaker" or, more accurately, a "conformation inducer," often causing kinks or bends in the polypeptide backbone.
These conformational preferences are not uniform across all proline-containing peptides. The specific amino acid sequence adjacent to the proline residue can influence the *cis/trans* ratio of the proline peptide bond. This sequence-dependent behavior means that the structural impact of proline can be fine-tuned by its surrounding amino acids, allowing for diverse roles in protein architecture.
The proline peptide bond also exhibits distinct chemical reactivity. For instance, aspartyl-proline peptide bonds have been observed to be particularly susceptible to hydrolysis under acidic conditions, a phenomenon where other aspartyl bonds remain stable.Effect of Proline and Glycine Residues on Dynamics and ... This anomalous cleavage highlights the unique lability of proline-containing peptide bonds under certain chemical environments.
Furthermore, specific chemical cleavage methods have been developed to target and break peptide bonds adjacent to proline residues. This targeted cleavage can be a useful tool in biochemical research for analyzing peptide sequences and understanding the structural roles of proline.
Proline's unusual properties make it a vital component in many biologically important peptides and proteinsPeptide bonds to proline, and to other N-substituted amino acids, are able to populate both the cis and trans isomers. .... Its ability to induce specific turns and kinks is crucial for the proper three-dimensional folding of proteins, influencing their interactions with other molecules and their overall functionMolecular insights into protein synthesis with proline residues - PMC. Proline-rich motifs are found in various signaling peptides and structural proteins, where their conformational constraints play essential roles作者：F Krieger·2005·被引用次数：309—Pseudo-proline (ΨPro) is known to increase the cis content of a Val-Pro peptide bond to about 80% due to steric effects induced by the methyl groups in the .... The *cis/trans* isomerization of proline peptide bonds is also implicated in various biological processes, including enzyme catalysis and signal transduction, where it can act as a regulatory switch.作者：J Alcantara·2021·被引用次数：17—One unique attribute of proline isits ability to isomerize around the peptide bondand sample a cis conformation. In the typical trans conformation of the ...
In summary, the peptide bond with proline is a subject of significant interest due to its unique structural, kinetic, and chemical properties. Its influence on peptide bond formation rate, conformational flexibility, and susceptibility to cleavage makes it a critical determinant of protein structure and function.
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