Conformations and Folding of Lysozyme Ions in vacuo

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 93; no. 7; pp. 3143 - 3148
• Main Authors: Gross, Deborah S., Schnier, Paul D., Rodriguez-Cruz, Sandra E., Fagerquist, Clifton K., Williams, Evan R.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 02.04.1996; National Acad Sciences; National Academy of Sciences
• Subjects: Animals; Charged particles; Chemical bases; Chemistry; Chickens; Crystal structure; Crystallography; Disulfides; Female; Fourier Analysis; Gases; Ions; Mass spectrometers; Mass Spectrometry - instrumentation; Mass Spectrometry - methods; Mass spectroscopy; Muramidase - chemistry; Protein Conformation; Protein Folding; Proteins; Protons; Reactivity; Solvents; Vapor phases
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.93.7.3143

Proton transfer reactivity of isolated charge states of the protein hen egg-white lysozyme shows that multiple distinct conformations of this protein are stable in the gas phase. The reactivities of the 9+ and 10+ charge state ions, formed by electrospray ionization of ``native'' (disulfide-intact) and ``denatured'' (disulfide-reduced) solutions, are consistent with values calculated for ions in their crystal structure and fully denatured conformations, respectively. Charge states below 8+ of both forms, formed by proton stripping, have similar or indistinguishable reactivities, indicating that the disulfide-reduced ions fold in the gas phase to a more compact conformation.