Protein Modification
Protein Modification - Related Videos
01:26
Protein Modifications in the RER
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2023
Modification of secretory and transmembrane proteins entering the rough ER begins in the ER lumen. These modifications aid in protein folding and stabilize the acquired tertiary structure. Protein modifications in the rough ER co-occur at different stages of protein folding. Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal sequences.
10:07
Identification of Post-translational Modifications of Plant Protein Complexes
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Cited by 8 •
2014
We describe here a protocol for the purification and characterization of plant protein complexes. We demonstrate that by immunoprecipitating a single protein within a complex, so we can identify its post-translational modifications and its interacting partners.
05:16
Detecting Histone Modifications in Yeast Cells with Neurodegenerative Protein Overexpression
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2025
Source: Bennett, S. A., et al., Characterizing Histone Post-translational Modification Alterations in Yeast Neurodegenerative Proteinopathy Models. J. Vis. Exp. (2019).This video demonstrates the procedure of assessing histone modifications in yeast cells overexpressing neurodegenerative proteins. The steps include cell lysis, centrifugation, electrophoresis, membrane transfer, and antibody-based detection of modified histones.
02:32
Histone Modification
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2020
The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression. Acetylation The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
02:25
Spreading of Chromatin Modifications
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2020
The histone proteins in the nucleosomes are post-translationally modified (PTM) to increase or decrease access to DNA. The commonly observed PTMs are methylation, acetylation, phosphorylation, and ubiquitination of lysine amino acids in the histone H3 tail region. These histone modifications have specific meaning for the cell. Hence, they are called "histone code". The protein complex involved in histone modification is termed as "reader-writer" complex. Writers The writer is an enzyme that can...
FAQs
Enzymatic routes use biological catalysts to alter proteins after translation, with examples including phosphorylation, acetylation, and ubiquitination. Direct chemical routes instead react with suitable side chains under defined conditions. This distinction lets researchers choose between biologically relevant changes and deliberately introduced chemical alterations, depending on whether the goal is to study regulation, attach a probe, or tune molecular behavior.
A change at an amino acid side chain, terminus, or structural region can influence a different property of the molecule. Depending on its location, the alteration may affect activity, stability, localization, or interactions. Controlling the site therefore helps researchers connect a specific chemical change with a structural or functional outcome rather than observing only an overall effect.
Chemical alteration can change how a protein folds, remains stable, or interacts with surrounding molecules. These structural consequences may influence binding, solubility, and biological activity, even when the protein’s amino acid sequence remains unchanged. Studying such changes allows chemistry-based experiments to investigate structure–function relationships and identify how molecular architecture contributes to protein behavior.
Direct chemical modification depends on reactive amino acid side chains and on conditions that support the intended reaction. Researchers must therefore define the chemical setting well enough to promote alteration of the target protein while preserving the property under investigation. This approach is useful for introducing labels, probes, drugs, or other chemical groups in a controlled experimental design.
A practical workflow begins by identifying the desired outcome, such as changing solubility, examining binding, or attaching an imaging probe. Researchers then select an enzymatic or direct chemical strategy, identify an appropriate residue, terminus, or structural target, and establish defined reaction conditions. Analytical characterization can then assess the resulting alteration and its effect on protein behavior.
Protein modification is useful when a biomolecule must carry a detectable chemical label or imaging probe without abandoning the property being studied. Modified proteins can support analytical methods for characterizing complex molecules and can help track interactions or localization. In this context, the chemical alteration becomes an experimental handle for obtaining information about protein structure and behavior.
Altering proteins can tune properties relevant to therapeutic design and biomaterials, including solubility, binding, stability, and interactions. Chemical attachment of drugs or imaging probes extends this role beyond basic characterization. These applications use controlled molecular changes to connect protein chemistry with the design of functional materials, therapeutic systems, and tools for studying complex biological molecules.
Chemistry provides ways to examine regulatory alterations such as phosphorylation, acetylation, and ubiquitination, which occur enzymatically after translation. By studying these changes and their consequences for activity, localization, stability, or interactions, researchers can investigate how protein behavior is regulated. Direct chemical reactions also provide complementary tools for probing the same structure–function relationships under defined experimental conditions.