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Fragmentation of biotinylated cyclic peptides
Michael E Lassman1, Nadia Kulagina, Chris Rowe Taitt
1Center for Biomolecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375, USA. Lassman@cbmse.nrl.navy.mil
Rapid Communications in Mass Spectrometry : RCM
|June 3, 2004
Summary
This study used mass spectrometry (MS/MS) to identify where biotin binds to polymyxin antibiotics. The results reveal preferred labeling sites on these cyclic peptides, aiding in understanding their structure and function.
Area of Science:
- Analytical Chemistry
- Biochemistry
- Mass Spectrometry
Background:
- Polymyxins are cyclic peptides with antibiotic properties produced by Bacillus polymyxa.
- Biotinylation is a common technique for labeling biomolecules.
- Determining specific binding sites on complex peptides can be challenging.
Purpose of the Study:
- To identify the preferred binding sites of biotin NHS ester on polymyxin peptides.
- To characterize the structure of biotinylated polymyxin peptides using MS/MS.
- To elucidate the fragmentation pathways of biotinylated cyclic peptides.
Main Methods:
- Electrospray ionization coupled with tandem mass spectrometry (MS/MS).
- Chemical labeling of polymyxin peptides with biotin NHS ester.
- Analysis of MS/MS fragmentation patterns of labeled peptides.
Main Results:
- Multiple biotin molecules were incorporated into intact polymyxin peptides, despite 1:1 stoichiometry.
- MS/MS analysis successfully characterized the structure of biotinylated polymyxin peptides.
- The complexity introduced by biotin aided in elucidating fragmentation pathways and identifying preferential binding sites.
Conclusions:
- Tandem mass spectrometry is effective for determining biotinylation sites on polymyxin peptides.
- The study rationalized the preferential binding sites of biotin on these cyclic antibiotics.
- Understanding these binding sites can contribute to further research on polymyxin structure-activity relationships.