Abstract
Liquid extraction surface analysis (LESA) mass spectrometry is a promising tool for the analysis of intact proteins from biological substrates. Here, we demonstrate native LESA mass spectrometry of noncovalent protein complexes of myoglobin and hemoglobin from a range of surfaces. Holomyoglobin, in which apomyoglobin is noncovalently bound to the prosthetic heme group, was observed following LESA mass spectrometry of myoglobin dried onto glass and polyvinylidene fluoride surfaces. Tetrameric hemoglobin [(αβ)24H] was observed following LESA mass spectrometry of hemoglobin dried onto glass and polyvinylidene fluoride (PVDF) surfaces, and from dried blood spots (DBS) on filter paper. Heme-bound dimers and monomers were also observed. The ‘contact’ LESA approach was particularly suitable for the analysis of hemoglobin tetramers from DBS.Graphical ᅟ
Highlights
S oon after its introduction, it was demonstrated that electrospray ionization (ESI) [1] was capable of retaining specific noncovalent interactions [2]
Native mass spectrometry is able to define the stoichiometry of protein subunits in a multi-protein complex and requires a fraction of the sample or analysis time required for NMR or X-ray crystallography [6]
We demonstrate that Liquid extraction surface analysis (LESA) mass spectrometry can be successfully applied to the analysis of noncovalent protein complexes directly from dried surfaces, including glass, polyvinylidene fluoride (PVDF), and dried blood spots (DBS) on filter paper
Summary
S oon after its introduction, it was demonstrated that electrospray ionization (ESI) [1] was capable of retaining specific noncovalent interactions [2]. Katta and Chait demonstrated ESI of holo-myoglobin (in which the apo-myoglobin is noncovalently bound to the prosthetic heme group) [3]. The literature abounds with examples of ESI mass spectrometry of protein–metal, protein–ligand, protein–DNA, and protein–protein complexes, and this field of research has been dubbed native mass spectrometry [5]. The conditions needed to retain a protein in its native (like) state are different from those used typically in ESI mass spectrometry. Buffers cannot contain organic solvent or have low pH. Such buffers unfold and protonate the protein, which does
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of the American Society for Mass Spectrometry
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
