| Autor: |
Chu, I. K., Rodriquez, C. F., Lau, T.-C., Hopkinson, A. C., Siu, K. W. M. |
| Zdroj: |
The Journal of Physical Chemistry - Part B; April 2000, Vol. 104 Issue: 15 p3393-3397, 5p |
| Abstrakt: |
An unprecedented method of producing molecular radical cations of oligopeptides in the gas phase has been discovered. Electrospraying a methanolic mixture of a Cu(II)−amine complex, e.g., CuII(dien)(NO3)2 (where dien = diethylenetriamine), and an oligopeptide (M) yields the [CuII(dien)M]•2+ ion, whose collision-induced dissociation (CID) produces [CuI(dien)]+ and M•+, the molecular cation of the oligopeptide. Abundant M•+ is apparent when the oligopeptide contains both a tyrosyl and a basic residue&sbd;arginyl, lysyl, or histidyl. These structural requirements are similar to those in the metalloradical enzyme process in photosystem II. Tandem mass spectrometry of M•+ produces fragment ions that are both common to and also different from [M + H]+. The fragmentation chemistry of M•+ and of its products appear to be radical driven. |
| Databáze: |
Supplemental Index |
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