Peptide Substrate
Peptide Substrate - Related Videos
03:05
Fluorescent Peptide Zymography: A Modified Technique to Detect Protease Activity Using Fluorogenic Substrates in Zymogram Gels
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2025
In this video, we perform zymography, an electrophoretic technique, to analyze the proteolytic activity within biological samples.
09:34
Identification of Modified Histones as Binding Substrates of Human Spindlin Family Member 4 (SPIN4) by Peptide Arrays and Native Nucleosome Pulldown
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2026
Genetic variants in human Spindlin Family Member 4 (SPIN4) have recently been identified in patients with bone overgrowth, a novel developmental disorder. A protocol and new results describing the biochemical identification of modified histones in the context of nucleosomes as SPIN4 binding substrates are presented.
04:00
Immunoaffinity Based Extraction of Ubiquitinylated Peptides: A Technique to Selectively Extract Ubiquitin Tagged Peptides from Purified Peptide Fractions
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2023
This video describes a method to extract and purify ubiquitinylated peptides containing remnant di-glycine peptides from a complex peptide mixture. The presented method may help in identifying original ubiquitination sites in the protein.
11:13
Identification of Kinase-substrate Pairs Using High Throughput Screening
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Cited by 1 •
2015
Protein phosphorylation is a central feature of how cells interpret and respond to information in their extracellular milieu. Here, we present a high throughput screening protocol using kinases purified from mammalian cells to rapidly identify kinases that phosphorylate a substrate(s) of interest.
05:21
A Peptide Microarray Technology for Specificity Profiling of Antibodies
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2025
This video demonstrates a technique that applies peptide microarray technology to profile the specificity of antibodies recognizing post-translational modifications (PTMs) on histone peptides. A microarray slide containing immobilized fluorophore-conjugated histone peptides with known PTM combinations is treated with target PTM-specific antibodies. This process helps identify the antibody's specificity for the target and its potential cross-reactivity with non-target PTMs.
FAQs
Recognition depends on more than the number of amino acids. The substrate’s amino acid sequence and three-dimensional context together determine how it fits the enzyme’s active site. This fit helps explain why changing the sequence or structural context can alter which enzyme reaction is observed, making peptide substrates useful for examining molecular recognition.
The active site positions the peptide substrate for a particular reaction. Depending on the enzyme, catalysis may cleave a peptide bond, add a phosphate group, or produce another defined modification. Identifying the resulting change connects the substrate’s molecular interaction with the enzyme’s function and allows researchers to distinguish different types of protein reactions.
Precisely designed sequences allow researchers to test how particular amino acid arrangements affect enzyme recognition and modification. By comparing defined substrates, investigators can relate sequence differences to changes in the reaction observed. This approach supports specificity studies because the peptide provides a controlled model for examining how enzymes distinguish potential targets.
In an enzyme activity assay, researchers expose a selected peptide substrate to an enzyme and measure the resulting chemical modification. The observed reaction provides evidence of enzyme activity and can be compared across enzymes or experimental conditions. Because the sequence is defined, the assay also helps connect activity with substrate recognition and reaction specificity.
Using the same or deliberately varied peptide sequences gives researchers a common basis for comparing enzymes. Differences in the chemical changes produced can reveal variation in molecular recognition, catalytic behavior, or substrate specificity. In biology, this makes peptide-based measurements useful for relating enzyme activity to the distinct functions of protein-modifying systems.
Protease studies use peptide substrates to examine which sequences undergo peptide-bond cleavage, while kinase screening examines addition of a phosphate group. The same controlled design principle supports inhibitor development by providing a measurable enzyme reaction to evaluate. These applications make peptide substrates useful biochemical tools for investigating enzyme specificity and identifying compounds that affect activity.