Dimethylation Labeling
Dimethylation Labeling - Related Videos
11:53
Quantitative Proteomics Using Reductive Dimethylation for Stable Isotope Labeling
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Cited by 38 •
2014
Stable isotope labeling of peptides by reductive dimethylation (ReDi labeling) is a rapid, inexpensive strategy for accurate mass spectrometry-based quantitative proteomics. Here we demonstrate a robust method for preparation and analysis of protein mixtures using the ReDi approach that can be applied to nearly any sample type.
13:59
Methods to Identify the NMR Resonances of the 13C-Dimethyl N-terminal Amine on Reductively Methylated Proteins
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Cited by 4 •
2013
Two methods for assigning the α- and ε-dimethylamine nuclear magnetic resonance signals of a reductively 13C-methylated N-terminal lysine are described. One method utilizes the pH-induced selectivity of the reductive methylation reaction, and the other uses aminopeptidase to selectively remove the N-terminal lysine.
02:35
Long-Term Cryopreservation of Cyanobacterial Strains Using Glycerol or Dimethyl Sulfoxide
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2025
Source: Lea-Smith, D. J., et al. Generation of Marked and Markerless Mutants in Model Cyanobacterial Species. J. Vis. Exp. (2016)This video demonstrates the cryopreservation of cyanobacterial strains by combining concentrated cell suspensions with glycerol or DMSO and storing them at low temperatures, enabling long-term maintenance of viable cultures for photosynthesis and genetic studies.
09:19
Simultaneous Label-Free Autofluorescence Multi-Harmonic Microscopy
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Cited by 3 •
2025
This protocol presents a step-by-step guide for the Simultaneous Label-free Autofluorescence Multi-harmonic (SLAM) microscopic technique, including details on how to generate the laser light source, prepare a tissue sample, conduct imaging, and analyze the data. SLAM advances nonlinear microscopy by measuring four complementary label-free contrasts to investigate the tissue microenvironment.
08:28
Metabolic Labeling
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2023
Metabolic labeling is used to probe the biochemical transformations and modifications that occur in a cell. This is accomplished by using chemical analogs that mimic the structure of natural biomolecules. Cells utilize analogs in their endogenous biochemical processes, producing compounds that are labeled. The label allows for the incorporation of detection and affinity tags, which can then be used to elucidate metabolic pathways using other biochemical analytical techniques, such as SDS-PAGE...
FAQs
Formaldehyde reacts with primary amines at peptide or protein N-termini and lysine residues, creating an intermediate that the reducing agent converts through reductive amination. This targeted chemistry introduces dimethyl groups at defined amine sites rather than labeling every type of residue. The resulting derivatization produces a predictable change that can be measured by mass spectrometry.
Different reagent forms produce distinct mass shifts after the labeling reaction. Light reagents and isotopically labeled alternatives therefore give chemically corresponding peptides or proteins distinguishable mass signatures. Multiple biological samples can be assigned different labeling forms, combined for analysis, and compared within the same mass spectrometry experiment using those reagent-dependent mass differences.
Predictable mass differences provide a consistent basis for recognizing corresponding labeled peptides or proteins and comparing their signals by mass spectrometry. Because the labels generate defined shifts, measurements can support relative quantification rather than only detection. This makes it possible to examine changes in protein or peptide abundance across biological samples and experimental conditions.
The reaction targets primary amino groups located at peptide or protein N-termini and on lysine residues. These sites provide the chemical handles for reductive amination with formaldehyde and a reducing agent. Their modification adds the dimethyl-derived mass signature used for subsequent mass spectrometric detection and comparison, while the site specificity supports consistent interpretation of labeled analytes.
A practical workflow uses formaldehyde together with a reducing agent to derivatize peptide or protein primary amines, selecting light or isotopically labeled reagents according to the comparison design. The labeled samples are then analyzed by mass spectrometry, where their distinct mass shifts support detection and relative comparison. The approach is suited to comparing multiple biological samples.
Researchers can use dimethylation labeling when they need relative comparisons of proteins or peptides across biological samples, including differences in expression, processing, or experimental conditions. Its accessible workflow, efficient reaction chemistry, and compatibility with quantitative proteomics make it useful when chemically introducing distinguishable mass signatures is preferable for organizing comparative mass spectrometry measurements.