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Methods to Identify the NMR Resonances of the 13C-Dimethyl N-terminal Amine on Reductively Methylated Proteins
Published on: December 12, 2013
The dansyl method for identifying N-terminal amino acids.
1School of Biological and Environmental Sciences, The Hatfield Polytechnic, Hatfield, Hertfordshire, England.
Methods in Molecular Biology (Clifton, N.J.)
|June 1, 2010
Summary
Dansyl chloride (DNS-C1) labels N-terminal amino acids in peptides and proteins. The resulting fluorescent dansyl amino acids are identified by chromatography, enabling sensitive amino acid analysis and peptide sequencing.
Area of Science:
- Biochemistry
- Analytical Chemistry
- Proteomics
Background:
- Peptide and protein analysis requires methods for N-terminal amino acid identification.
- Existing methods may lack sensitivity or applicability to both peptides and proteins.
Purpose of the Study:
- To describe a sensitive method for N-terminal amino acid identification using dansyl chloride.
- To highlight the utility of this technique in peptide sequencing.
Main Methods:
- Reaction of N-terminal amino groups with dansyl chloride (DNS-C1).
- Acid hydrolysis of dansyl-labeled peptides/proteins.
- Identification of dansyl amino acids via thin-layer chromatography on polyamide sheets.
Main Results:
- Dansyl chloride selectively labels free amino groups.
- The dansyl-N-terminal amino acid bond is stable to acid hydrolysis.
- Dansyl amino acids exhibit fluorescence under UV light, allowing sensitive detection.
Conclusions:
- The dansyl technique provides a highly sensitive method for identifying N-terminal amino acids in peptides and proteins.
- This method is valuable for peptide sequence determination, especially when combined with Edman degradation.
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