The pH Dependence of Product Ion Spectra Obtained from Precursor Ions with the Same Charge Number in ESI of Carbonic Anhydrase 2

Nabuchi, Yoshiaki; Hirose, Koichi; Takayama, Mitsuo

doi:10.5702/massspectrometry.a0016

Cited by 2 publications

(1 citation statement)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“… 22 ) From the product ion spectra obtained under several different solvent conditions, we showed that the folding states of the C-terminal region of the protein were influenced by the solvent. 23 , 24 ) However, the relationship between the folding states of CA2 ions and their molecular size have not yet been examined.…”

Section: Introductionmentioning

confidence: 99%

pH Dependence of the Number of Discrete Conformers of Carbonic Anhydrase 2, as Evaluated from Collision Cross-Section Using Ion Mobility Coupled with Electrospray Ionization

2018

Self Cite

View full text Add to dashboard Cite

Ion mobility experiments coupled with electrospray ionization (ESI) were conducted to evaluate the folding states of bovine carbonic anhydrase 2 (CA2) under three different pH conditions. Collision cross-section (CCS) of the CA2 ions generated by ESI revealed the presence of six discrete conformers in the gas phase under the conditions employed in this study. The CCS of the most extended conformer was three times larger than that of the most compact one. The charge state distribution of the CA2 ions was indicative of three conformers being present. Although there was consistency in conformer assignment conducted by CCS and charge state distribution, the CCS measurement was shown to be more effective because the information obtained provided more detailed knowledge of the conformation of the protein.

show abstract

Section: Introductionmentioning

confidence: 99%

pH Dependence of the Number of Discrete Conformers of Carbonic Anhydrase 2, as Evaluated from Collision Cross-Section Using Ion Mobility Coupled with Electrospray Ionization

2018

Self Cite

View full text Add to dashboard Cite

show abstract

Resolving the Discrepancies Between Empirical and Rayleigh Charge Limiting Models for Globular Proteins

Freitas

2018

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

Starting with the Rayleigh charge limiting model, a slightly different approach is used to account for the well-known discrepancy that exists between the said model and experimental ESI MS data for globular proteins. It is shown using published datasets that for globular proteins, the mass density ρ exhibits a weak second-order dependence on its mass M, according to ρ(M)∝ M, α ~ 0.14. A direct equivalence established between ESI MS and x-ray techniques suggests a minimum but critical surface tension of 15.6 ± 5.2 mN/m for the droplet at the liquid-to-gas phase transition point. The packing density factor η for globular proteins is believed to lie between 1 (very tightly packed) and 4.6 (less tight, natively packed). While the Rayleigh charge limiting model has been linked historically to the CRM (J. Chem. Phys. 49:2240-2249, 1968; Anal. Chim. Acta 406:93-104, 2000), this paper does not expressly seek to justify the CRM, but rather uses empirical data and existing knowledge across subfields to help build a consistent picture of ESI MS phenomena that might be difficult to explain otherwise. These results would be useful in molecular dynamics (MD) simulations, understanding liquid-to-gas phase transitions and in opening up new routes for cross-calibration between ESI MS, IM MS, NMR and x-ray crystallography studies. Graphical Abstract ᅟ.

show abstract

The pH Dependence of Product Ion Spectra Obtained from Precursor Ions with the Same Charge Number in ESI of Carbonic Anhydrase 2

Cited by 2 publications

References 23 publications

pH Dependence of the Number of Discrete Conformers of Carbonic Anhydrase 2, as Evaluated from Collision Cross-Section Using Ion Mobility Coupled with Electrospray Ionization

pH Dependence of the Number of Discrete Conformers of Carbonic Anhydrase 2, as Evaluated from Collision Cross-Section Using Ion Mobility Coupled with Electrospray Ionization

Resolving the Discrepancies Between Empirical and Rayleigh Charge Limiting Models for Globular Proteins

Contact Info

Product

Resources

About