1. A strategy for the identification of protein architectures directly from ion mobility mass spectrometry data reveals stabilizing subunit interactions in light harvesting complexes
- Author
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Mihkel Saluri, Michael Landreh, Cagla Sahin, Erik G. Marklund, and Margit Kaldmäe
- Subjects
Models, Molecular ,Ion-mobility spectrometry ,collision cross sections ,Protein subunit ,Full‐Length Papers ,protein complex stability ,Protein Data Bank (RCSB PDB) ,Light-Harvesting Protein Complexes ,macromolecular substances ,Cyanobacteria ,Biochemistry ,protein interactions ,Mass Spectrometry ,Protein–protein interaction ,Light-harvesting complex ,03 medical and health sciences ,ion mobility ,Full‐Length Paper ,Structural Biology ,Phycocyanin ,Molecular Biology ,030304 developmental biology ,red algae ,Strukturbiologi ,0303 health sciences ,Chemistry ,Protein Stability ,030302 biochemistry & molecular biology ,Biochemistry and Molecular Biology ,computer.file_format ,Hydrogen-Ion Concentration ,Protein Data Bank ,Protein Subunits ,Structural biology ,Rhodophyta ,structural mass spectrometry ,Biophysics ,computer ,Biokemi och molekylärbiologi - Abstract
Biotechnological applications of protein complexes require detailed information about their structure and composition, which can be challenging to obtain for proteins from natural sources. Prominent examples are the ring‐shaped phycoerythrin (PE) and phycocyanin (PC) complexes isolated from the light‐harvesting antennae of red algae and cyanobacteria. Despite their widespread use as fluorescent probes in biotechnology and medicine, the structures and interactions of their noncrystallizable central subunits are largely unknown. Here, we employ ion mobility mass spectrometry to reveal varying stabilities of the PC and PE complexes and identify their closest architectural homologues among all protein assemblies in the Protein Data Bank (PDB). Our results suggest that the central subunits of PC and PE complexes, although absent from the crystal structures, may be crucial for their stability, and thus of unexpected importance for their biotechnological applications.
- Published
- 2019