Department of Pharmacy, Laboratory of Pharmacokinetics, University of Patras, Greece
ileontari@upatras.gr
Dr. I. Leontari earned her Bachelor degree in Biology from the University of Ancona-Italy in 2002 and received her Master Degree in ‘‘Clinical Biochemistry and Immunochemistry – Microbial Biotechnology” from University of Ioannina in 2005. During her master’s thesis she investigated the role of conformation in the function of the biomolecules. The work gave her a very basic understanding in how functional data can be garnered through the identification, production and characterization of proteins. Based on her background in biology, she became strongly interested in Structural Proteomics. After her Master’s she decided to perusing her PhD in the Center of Magnetic Resonance (CERM) of University of Florence which suited her requirement and from 2004-2006 she was awarded a Marie Curie fellowship for research training in CERM Institute. Her PhD thesis focused on proteins involved in several pathways responsible of human copper homeostasis (SCO1, SCO2 and Cox17). Natural mutations in these proteins lead to disease. The objective of her research was to investigate the native proteins and their mutant forms, as well as to determine the relation between illness and the biophysical characteristics and structure of these proteins. During her doctoral studies she became familiar, on the one hand, with a variety of basic techniques of Molecular Biology and biotechnology and on another hand, with Spectroscopic techniques such as NMR and Mass Spectrometry. Furthermore, she has developed good expertise in chromatography techniques including affinity and reversed-phase chromatography. Since 2008, she is working as a postdoc in the Laboratory of Pharmacokinetics at Department of Pharmacy, University of Patras. The laboratory’s key research activities include preclinical and clinical studies of bioavailability and pharmacokinetics of new chemical entities
Abstract: The pathogenic mutant (P174L) of human Sco1 produces respiratory
chain deficiency associated with cytochrome c oxidase (CcO)
assembly defects. The solution structure of the mutant in its Cu(I)
form shows that Leu-174 prevents the formation of a well packed
hydrophobic region around the metal-binding site and causes a
reduction of the affinity of copper(I) for the protein. KD values for
Cu(I)WT-HSco1 and Cu(I)P174L-HSco1 are 1017 and 1013, respectively.
The reduction potentials of the two apo proteins are
similar, but slower reduction/oxidation rates are found for the
mutant with respect to the WT. The mitochondrial metallochaperone
in the partially oxidized Cu1(I)Cox172S-S form, at
variance with the fully reduced Cu4(I)Cox17, interacts transiently
with both WT-HSco1 and the mutant, forming the Cox17/Cu(I)/
HSco1 complex, but copper is efficiently transferred only in the
case of WT protein. Cu1(I)Cox172S-S indeed has an affinity for
copper(I) (KD 1015) higher than that of the P174L-HSco1 mutant
but lower than that of WT-HSco1. We propose that HSco1 mutation,
altering the structure around the metal-binding site, affects
both copper(I) binding and redox properties of the protein, thus
impairing the efficiency of copper transfer to CcO. The pathogenic
mutation therefore could (i) lessen the Sco1 affinity for copper(I)
and hence copper supply for CcO or (ii) decrease the efficiency of
reduction of CcO thiols involved in copper binding, or both effects
could be produced by the mutation.
Notes: Mitochondrial copper(I) transfer from Cox17 to Sco1 is coupled to electron transfer
Abstract: Human Sco2 is a mitochondrial membrane-bound protein involved in copper supply for the assembly of cytochrome c oxidase in eukaryotes. Its precise action is not yet understood. We report here a structural and dynamic characterization by NMR of the apo and copper(I) forms of the soluble fragment. The structural and metal binding features of human Cu(I)Sco2 are similar to the more often studied Sco1 homolog, although the dynamic properties and the conformational disorder are quite different when the apo forms and the copper(I)-loaded forms of the two proteins are compared separately. Such differences are accounted for in terms of the different physicochemical properties in strategic protein locations. The misfunction of the known pathogenic mutations is discussed on the basis of the obtained structure.
Notes: A structural-dynamical characterization of human Cox17.
Copper chaperones, intracellular copper trafficking proteins. Function, structure, and mechanism of action
