Dissecting heterogeneous molecular chaperone complexes using a mass spectrum deconvolution approach
| Autor: | Justin L. P. Benesch, Andrew Baldwin, Gillian R. Hilton, Elizabeth Vierling, Matthew F. Bush, Florian Stengel, Eman Basha, Hadi Lioe, Nomalie Jaya |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Clinical Biochemistry
Mass spectrometry 01 natural sciences Biochemistry Article Mass Spectrometry 03 medical and health sciences Drug Discovery Denaturation (biochemistry) Molecular Biology 030304 developmental biology Plant Proteins Pharmacology 0303 health sciences Chemistry 010401 analytical chemistry Peas General Medicine 0104 chemical sciences Heat-Shock Proteins Small Mass spectrum Biophysics Molecular Medicine Deconvolution Algorithms |
| Popis: | Small Heat-Shock Proteins (sHSPs) are a family of molecular chaperones that help prevent irreversible aggregation through binding non-native target proteins to form large and heterogeneous complexes. These sHSP:target complexes are an integral part of the overall proteostasis network but, due to their polydispersity, their composition and assembly remain poorly understood. Here, we present a novel nanoelectrospray mass spectrometry analysis algorithm for estimating the distribution of stoichiometries comprising a polydisperse ensemble of oligomers. We apply our approach to elucidate the organization of complexes formed between sHSPs and different target proteins. We find that protection of targets is mass-dependent, with the resultant complexes nonetheless reflecting properties of the target. Strikingly, we observe that aspects of the native quaternary architecture of the targets are retained, indicating that protection happens early in the denaturation process. Our data therefore explain the apparent paradox of how variable complex morphologies result from the generic mechanism of target protection afforded by the sHSPs. Our approach is applicable to a wide range of polydisperse proteins, and, more generally, provides a means for the automated and accurate interpretation of mass spectra derived from heterogeneous protein assemblies. |
| Databáze: | OpenAIRE |
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