title: Real-time monitoring of protein complexes reveals their quaternary organization and dynamics.
abstract: The dynamics of protein complexes are crucial for their function yet are challenging to study. Here, we present a nanoelectrospray (nESI) mass spectrometry (MS) approach capable of simultaneously providing structural and dynamical information for protein complexes. We investigate the properties of two small heat shock proteins (sHSPs) and find that these proteins exist as dodecamers composed of dimeric building blocks. Moreover, we show that these proteins exchange dimers on the timescale of minutes, with the rate of exchange being strongly temperature dependent. Because these proteins are expressed in the same cellular compartment, we anticipate that this dynamical behavior is crucial to their function in vivo. Furthermore, we propose that the approach used here is applicable to a range of nonequilibrium systems and is capable of providing both structural and dynamical information necessary for functional genomics.
authors: Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, United Kingdom.
authors: Alexander J
authors: AJ
authors: Painter
authors: Nomalie
authors: N
authors: Jaya
authors: Eman
authors: E
authors: Basha
authors: Elizabeth
authors: E
authors: Vierling
authors: Carol V
authors: CV
authors: Robinson
authors: Justin L P
authors: JL
authors: Benesch
mesh_terms: D017360:Arabidopsis / Q000378:metabolism; D045304:Cytochromes c / Q000378:metabolism; D050888:Heat-Shock Proteins, Small / Q000737:chemistry / Q000378:metabolism; D046912:Multiprotein Complexes / Q000737:chemistry* / Q000378:metabolism*; D036103:Nanotechnology; D010940:Plant Proteins / Q000378:metabolism; D020836:Protein Structure, Quaternary; D012371:Robotics; D021241:Spectrometry, Mass, Electrospray Ionization; D014357:Trypsin / Q000378:metabolism
chemical_list: D050888:Heat-Shock Proteins, Small; D046912:Multiprotein Complexes; D010940:Plant Proteins; D045304:Cytochromes c; D014357:Trypsin