Isopeptide bond example
An isopeptide bond is a specific type of amide linkage that plays a crucial role in protein structure and function. Unlike the standard peptide bond that connects the alpha-carboxyl group of one amino acid to the alpha-amino group of another along the main protein chain, an isopeptide bond forms between a carboxyl group and an amino group that are part of an amino acid's side chain, or between a side chain and a main chain terminus. This distinction is key to understanding the unique properties and applications of proteins containing these linkages, particularly in areas like protein crosslinking and stability.
The formation of isopeptide bonds is a common post-translational modificationDe Novo Design of Proteins for Autocatalytic Isopeptide Bond .... These bonds are known for their chemical stability and resistance to degradation by many proteases, which are enzymes that break down proteins.Intramolecular isopeptide bonds: protein crosslinks built for ... This inherent robustness makes them valuable for creating stable protein structures and crosslinked protein networks.
Isopeptide bonds are essentially amide bonds, sharing the same fundamental chemical structure as peptide bonds.An isopeptidase is a protease enzyme that hydrolyzesisopeptide bonds, or amide bonds that occur outside the main chain in a polypeptide chain. However, their location and the residues involved differ significantly.Site-Specific Isopeptide Bond Formation: A Powerful Tool for ... The most commonly observed isopeptide bond in biological systems is formed between the epsilon-amino group of a lysine residue and the side-chain carboxyl group of an aspartate or asparagine residue.2016年11月28日—Here, we will set up a diubiquitin system with a K11isopeptidelinkage joining two chains. The info here can be applied to any systems that have residues that ... This specific linkage is often formed autocatalytically within a protein or through enzymatic action.
Another prominent example involves the ubiquitin protein.作者：H Kwon·2017·被引用次数：20—We report the first example of anisopeptidebond engineered de novo into an immunoglobulin-like protein, the minor pilin FctB from Streptococcus pyogenes. Ubiquitin can form polyubiquitin chains linked by isopeptide bonds, typically between the C-terminus of one ubiquitin molecule and a lysine side chain of another.3天前—In the intricate world of biochemistry, bonds between amino acids form the backbone of protein structure and function. Among these connections, two types stand out: peptide bonds andisopeptidebonds. While they may sound similar, their formation and implications are quite distinct. These linkages are critical for signaling pathways within the cell.
While the term "isopeptide" might suggest a simple variation, the implications of these bonds are profound. They contribute to the structural integrity of proteins, can mediate protein-protein interactions, and are essential for the formation of complex protein assembliesIsopeptide bond.
The fundamental difference between an isopeptide bond and a standard peptide bond lies in their point of connection.The de-amidation (loss of amine) of the Asn-Gly sequence forms a cyclic imide intermediate that is subsequently hydrolyzed to form the aspartate oriso- ...
* Peptide Bond: Connects the alpha-carboxyl group of one amino acid to the alpha-amino group of the next amino acid, forming the linear backbone of a polypeptide chainIsopeptag | MyBioSource Learning Center. This is the primary linkage in proteins.Isopeptideproteins represent a fascinating area of study in the field of molecular biology and biochemistry. To understand what is meant byisopeptide, it's ...
* Isopeptide Bond: Forms between a carboxyl group and an amino group that are not part of the main alpha-carbon backboneIsopeptideproteins represent a fascinating area of study in the field of molecular biology and biochemistry. To understand what is meant byisopeptide, it's .... This typically involves amino acid side chains (like lysine, aspartate, or asparagine) or the termini of peptide chains.
This difference in connectivity leads to distinct structural outcomes.作者：NA Wani·2022·被引用次数：24—A site-specific approach is used to generate new AMPs to improve their efficacy against bacterial pathogens while reducing their toxicity. Peptide bonds create the linear sequence, while isopeptide bonds can introduce crosslinks, loops, or branches, significantly altering a protein's three-dimensional shape and stability. For instance, intramolecular isopeptide bonds can stabilize protein structures by creating covalent crosslinks within a single polypeptide chain, enhancing resistance to unfolding. Intermolecular isopeptide bonds can link separate protein molecules together, forming larger complexes or networks.
The biological significance of isopeptide bonds is evident in various contexts:
* Protein Stability: Many extracellular proteins and structural proteins rely on isopeptide bonds for their mechanical strength and resistance to denaturation.作者：L Tan·2011·被引用次数：27—Isopeptidebond formation is a general posttranslational protein modification in which an amide linkage occurs between an amino group of one ... For example, collagen, a key structural protein in connective tissues, contains internal isopeptide bonds that enhance its tensile strength.
* Ubiquitination: As mentioned, the ubiquitin-proteasome system heavily utilizes isopeptide bonds to link ubiquitin molecules together into chains.Isopeptide Bond - an overview These chains act as signals for protein degradation, cellular signaling, and DNA repair.
* Bacterial Pili: Some bacterial pili, which are hair-like appendages involved in adhesion and motility, are stabilized by isopeptide bonds, contributing to their structural integrity and function.作者：U Sridharan·2016·被引用次数：27—The internal isopeptide bonds areamide bonds formed autocatalytically between the side chains of Lys and Asn/Asp residuesand have been discovered recently.
* Enzyme Activity: Certain enzymes, such as transglutaminases, catalyze the formation of isopeptide bonds, playing roles in blood clotting, tissue repair, and cell adhesion.
The study of isopeptide bonds also extends to the realm of protein engineering and synthetic biology, where researchers are exploring ways to engineer these stable linkages for novel applications, such as creating self-assembling protein materials or improving the efficacy of therapeutic peptides.
In summary, an isopeptide bond is a crucial type of amide linkage that differs from the standard peptide bond by involving amino acid side chains or termini. These stable bonds are vital for enhancing protein structural integrity, mediating protein interactions, and enabling essential biological processes like ubiquitination. Understanding the formation and function of isopeptide bonds provides valuable insights into protein chemistry, molecular biology, and the development of new biotechnological tools.
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