Solvent-induced structural transitions of lysozyme in an electrospray ionization source.
نویسندگان
چکیده
The structural characterization of proteins using electrospray ionization mass spectrometry (ESI-MS) has become an important method for understanding protein structural dynamics. The correlation between the structures of proteins in solution and gas phase needs to be understood for the application of ESI-MS to protein structural studies. Hen egg white lysozyme (Lyz) is a small protein with a stable compact structure in solution. Although it was known that denatured Lyz in solution undergoes compaction during transfer into the gas phase via ESI, detailed characterization of the process was not available. In the present study, we show that the organic cosolvent, which denatures Lyz in solution, induces the collapse of the extended Lyz structure into compact structures during ESI. This process is further facilitated by the presence of acids, whose conjugate bases can interact with Lyz to reduce its charge state and the electrostatic repulsion between its charged residues (Analyst, 2015, 140, 661-669). Exposure of ESI droplets to acid and solvent vapors confirms that the overall process most probably occurs in the charged droplets from ESI. This study provides a detailed understanding of the possible influence of the solvent environment on protein structure during transfer into the gas phase.
منابع مشابه
Investigating Solvent-Induced Structural Transitions of Lysozyme in an Electrospray Ionization Source
متن کامل
Investigating acid-induced structural transitions of lysozyme in an electrospray ionization source.
The effect of acids on the structure of lysozyme (Lyz) during electrospray ionization (ESI) was studied by comparing the solution and gas-phase structures of Lyz. Investigation using circular dichroism spectroscopy and small-angle X-ray scattering demonstrated that the folded conformation of Lyz was maintained in pH 2.2 solutions containing different acids. On the other hand, analysis of the ch...
متن کاملLiquid-Sheath-Flow Electrospray Ionization Feasibility Study of Direct Water Analysis with the Use of High-Resolution Ion-Mobility Spectrometry
Ion-mobility spectrometry (IMS) in conjunction with radioactive ionization sources has been employed for field-portable applications for the past two decades. Recently, electrospray ionization (ESI) sources have been shown as a viable ionization source with IMS instruments, enabling the analysis of many nonvolatile compounds. Introduction of a liquid-sheath-flow ESI source enabled the direct an...
متن کاملCoupling desorption electrospray ionization with ion mobility/mass spectrometry for analysis of protein structure: evidence for desorption of folded and denatured States.
A desorption electrospray ionization (DESI) source has been coupled to an ion mobility time-of-flight mass spectrometer for the analysis of proteins. Analysis of solid-phase horse heart cytochrome c and chicken egg white lysozyme proteins with different DESI solvents and conditions shows similar mass spectra and charge state distributions to those formed when using electrospray to analyze these...
متن کاملElectrospray ionization-multistage tandem mass spectrometry of complex multitin organometallic compounds.
The series of 14 complex organotin(IV) compounds containing many tin atoms and noncovalent bonds in the structure was characterized by electrospray ionization multistage tandem mass spectrometry (ESI-MS(n)). The mass spectra were measured in both polarity modes to obtain complementary structural information. The characteristic pattern of ten natural tin isotopes allowed the determination of the...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- The Analyst
دوره 140 10 شماره
صفحات -
تاریخ انتشار 2015