Native Electron Capture Dissociation for the Structural Characterization of Noncovalent Interactions in Native Cytochrome c


  • The authors acknowledge generous funding from the Austrian Science Foundation (FWF grant P15767 to KB) and the National Institutes of Health (NIH grant GM16609 to FWM), and thank Dr. Rich Knochenmuss, Prof. Dr. Bernhard Kräutler, Huili Zhai, Dr. Vlad Zabrouskov, Dr. Cheng Lin, and Xuemei Han for discussions and Pieter Dörrestein for recording solution UV/Vis spectra.


original image

Selectively cleaved: Under appropriate experimental conditions, electrospray ionization mass spectrometry produces fragment ions that directly indicate noncovalent protein–heme interaction sites in native Cytochrome c (see picture). The proposed mechanism involves asymmetric charge partitioning in gaseous protein dimer ions, which causes electron transfer and subsequent backbone-cleavage.