title: Structural alterations induced by ten disease-causing mutations of human dihydrolipoamide dehydrogenase analyzed by hydrogen/deuterium-exchange mass spectrometry: Implications for the structural basis of E3 deficiency.
abstract: Pathogenic amino acid substitutions of the common E3 component (hE3) of the human alpha-ketoglutarate dehydrogenase and the pyruvate dehydrogenase complexes lead to severe metabolic diseases (E3 deficiency), which usually manifest themselves in cardiological and/or neurological symptoms and often cause premature death. To date, 14 disease-causing amino acid substitutions of the hE3 component have been reported in the clinical literature. None of the pathogenic protein variants has lent itself to high-resolution structure elucidation by X-ray or NMR. Hence, the structural alterations of the hE3 protein caused by the disease-causing mutations and leading to dysfunction, including the enhanced generation of reactive oxygen species by selected disease-causing variants, could only be speculated. Here we report results of an examination of the effects on the protein structure of ten pathogenic mutations of hE3 using hydrogen/deuterium-exchange mass spectrometry (HDX-MS), a new and state-of-the-art approach of solution structure elucidation. On the basis of the results, putative structural and mechanistic conclusions were drawn regarding the molecular pathogenesis of each disease-causing hE3 mutation addressed in this study.
authors.affiliation: Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest, Hungary. Electronic address: ambrus.attila@med.semmelweis-univ.hu.
authors.forename: Attila
authors.initials: A
authors.lastname: Ambrus
authors.affiliation: Department of Chemistry, Rutgers University, Newark, NJ, USA.
authors.forename: Junjie
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest, Hungary.
authors.forename: Reka
authors.initials: R
authors.lastname: Mizsei
authors.affiliation: Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest, Hungary.
authors.forename: Zsofia
authors.initials: Z
authors.lastname: Zambo
authors.affiliation: Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest, Hungary.
authors.forename: Beata
authors.initials: B
authors.lastname: Torocsik
authors.affiliation: Department of Chemistry, Rutgers University, Newark, NJ, USA. Electronic address: frjordan@rutgers.edu.
authors.forename: Frank
authors.initials: F
authors.lastname: Jordan
authors.affiliation: Department of Medical Biochemistry, MTA-SE Laboratory for Neurobiochemistry, Semmelweis University, Budapest, Hungary. Electronic address: adam.veronika@med.semmelweis-univ.hu.
authors.forename: Vera
authors.initials: V
authors.lastname: Adam-Vizi
keywords: Dihydrolipoamide dehydrogenase; E3 deficiency; Hydrogen/deuterium exchange; Mass spectrometry; Pathogenic mutation