Metal-coded affinity tag is a method used for
quantitative proteomics
Quantitative proteomics is an analytical chemistry technique for determining the amount of proteins in a sample. The methods for protein identification are identical to those used in general (i.e. qualitative) proteomics, but include quantificatio ...
by
mass spectrometry that uses a metal chelate complex
1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate
DOTA (also known as tetraxetan) is an organic compound with the formula (CH2CH2NCH2CO2H)4. The molecule consists of a central 12-membered tetraaza (i.e., containing four nitrogen atoms) ring. DOTA is used as a complexing agent, especially for lant ...
(DOTA) coupled to different
lanthanide ions.
The metal complexes attach to the
cysteine residues of
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...
s in a sample.
Proteomic analysis
For
bottom-up proteomics, the proteins can be separated by
two-dimensional gel electrophoresis
Two-dimensional gel electrophoresis, abbreviated as 2-DE or 2-D electrophoresis, is a form of gel electrophoresis commonly used to analyze proteins. Mixtures of proteins are separated by two properties in two dimensions on 2D gels. 2-DE was first ...
and analyzed by
matrix-assisted laser desorption/ionization
In mass spectrometry, matrix-assisted laser desorption/ionization (MALDI) is an ionization technique that uses a laser energy absorbing matrix to create ions from large molecules with minimal fragmentation. It has been applied to the analysis of ...
(MALDI) or
electrospray ionization
Electrospray ionization (ESI) is a technique used in mass spectrometry to produce ions using an electrospray in which a high voltage is applied to a liquid to create an aerosol. It is especially useful in producing ions from macromolecules becaus ...
mass spectrometry for relative quantification or by
inductively coupled plasma mass spectrometry
Inductively coupled plasma mass spectrometry (ICP-MS) is a type of mass spectrometry that uses an inductively coupled plasma to ionize the sample. It atomizes the sample and creates atomic and small polyatomic ions, which are then detected. It is ...
for absolute quantification. For
top-down proteomics
Top-down proteomics is a method of protein identification that either uses an ion trapping mass spectrometer to store an isolated protein ion for mass measurement and tandem mass spectrometry (MS/MS) analysis or other protein purification methods ...
, the undigested labeled proteins are analyzed.
See also
*
Mass cytometry
Mass cytometry is a mass spectrometry technique based on inductively coupled plasma mass spectrometry and time of flight mass spectrometry used for the determination of the properties of cells (cytometry). In this approach, antibodies are conju ...
References
Mass spectrometry
Proteomics
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