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Chemistry

2019

Chemistry Publications

Protein Conformation

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Mechanism Of Electrospray Supercharging For Unfolded Proteins: Solvent-Mediated Stabilization Of Protonated Sites During Chain Ejection., Insa Peters, Haidy Metwally, Lars Konermann May 2019

Mechanism Of Electrospray Supercharging For Unfolded Proteins: Solvent-Mediated Stabilization Of Protonated Sites During Chain Ejection., Insa Peters, Haidy Metwally, Lars Konermann

Chemistry Publications

Proteins that are unfolded in solution produce higher charge states during electrospray ionization (ESI) than their natively folded counterparts. Protein charge states can be further increased by the addition of supercharging agents (SCAs) such as sulfolane. The mechanism whereby these supercharged [M + zH] z+ ions are formed under unfolded conditions remains unclear. Here we employed a combination of mass spectrometry (MS), ion mobility spectrometry (IMS), and molecular dynamics (MD) simulations for probing the ESI mechanism under denatured supercharging conditions. ESI of acid-unfolded apo-myoglobin (aMb) in the presence of sulfolane produced charge states around 27+, all the way to fully …


Protein Ions Generated By Native Electrospray Ionization: Comparison Of Gas Phase, Solution, And Crystal Structures., Maryam Bakhtiari, Lars Konermann Feb 2019

Protein Ions Generated By Native Electrospray Ionization: Comparison Of Gas Phase, Solution, And Crystal Structures., Maryam Bakhtiari, Lars Konermann

Chemistry Publications

Experiments and molecular dynamics (MD) simulations in the literature indicate that gaseous proteins generated by electrospray ionization (ESI) can retain native-like structures. However, the exact properties of these ions remain to be explored. Focusing on ubiquitin and lysozyme, we examined several pertinent questions. (1) We applied solvent MD runs to test whether the X-ray structures of both proteins are affected by crystal packing. Main and side-chain orientations were retained in solution, providing a justification for the hitherto unscrutinized approach of relying on crystal data for "solution" versus gas-phase comparisons. (2) Most earlier gas-phase protein MD investigations employed short (ns) simulation …