|
Eur. J. Mass Spectrom. DOI: 10.1255/ejms.652 |
|
Mss spectrometry analysis of synthetically myristoylated peptides | ||
Tsefang S. Chen, Jennifer D. Yoder, and Dennis E. Hruby* |
||
ABSTRACT: | ||
Myristoylpeptides were synthesized in order to determine if a neutral loss of 210 Da, C14H26O (the mass of the myristoyl moiety), was universal and observable by both liquid chromatography electrospray ionization quadrapole ion trap (LC-ESI-QIT) and matrix assisted laser desorption ionization (MALDI-ToF-ToF) mass spectrometry. Myristoylation was successfully introduced on the N-terminus, internally on the amino group of lysine and arginine. Larger peptides and the arginine compounds needed elevated temperatures for myristoylation. To our knowledge, this is the first report of a chemically synthesized myristoylated arginine in a peptide. Collision energy studies for the LC-ESI-QIT instrument showed that modified peptides and a loss of 210 Da could be detected under commonly used conditions (energy level between 30 to 42%) with picomole amounts of sample. The loss of myristoyl moiety is observed on the MALDI-ToF-ToF mass spectrometer as well. Due to the hydrophobic properties of the myristoyl moiety, it is not surprising that the modified peptides all formed at least dimers, and in some cases trimers. We were also able to distinguish a mixture of two mono-myristoylated peptides. MS3 data from the LC-ESI-QIT instrument on a di-myristoylated peptide indicates the loss of 210 Da at either N-terminus or lysine. We were also able to analyze a mixture of modified and unmodified peptides on the MALDI ToF-ToF insturment. The data presented in this paper demonstrates the constant neutral loss of the 210 Da, C14H26O, from both N-terminally and internally myristoylated peptides can be identified unambiguously using LC-ESI-QIT or MALDI-ToF-ToF mass spectrometer. This will be a useful tool in determining the myristoylation status of candidate proteins after enzyme digestion, and in elucidating the modification sites of internal myristoylproteins. | ||
Keywords: Myristoylation, fatty acid acylation, acylprotein, myristic acid, LC-ESI-QIT mass spectrometry, MALDI-ToF-ToF mass spectrometry |
You can now buy this paper on-line in PDF format; it costs only £11.75. Just click on the BUY on-line button. You can pay on-line through a secure server and get access immediately.
© IM Publications Any problems? E-mail . |
![]() |