Stability of the Plasmodium falciparum AMA1-RON2 Complex Is Governed by the Domain II (DII) Loop

Autor: Michelle L. Parker, Roberto F. Delgadillo, Dominique Douguet, Martin J. Boulanger, Maryse Lebrun
Přispěvatelé: Institut de pharmacologie moléculaire et cellulaire (IPMC), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), University of Victoria [Canada] (UVIC), Dynamique des interactions membranaires normales et pathologiques (DIMNP), Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Models
Molecular
0301 basic medicine
Molecular Sequence Data
Plasmodium falciparum
Protozoan Proteins
lcsh:Medicine
Antigens
Protozoan
Receptors
Cell Surface
Plasma protein binding
[CHIM.THER]Chemical Sciences/Medicinal Chemistry
Calorimetry
Biology
Protein Structure
Secondary
03 medical and health sciences
Protein Interaction Domains and Motifs
Amino Acid Sequence
Apical membrane antigen 1
Binding site
lcsh:Science
Peptide sequence
ComputingMilieux_MISCELLANEOUS
Host cell membrane
Binding Sites
Multidisciplinary
Protein Stability
lcsh:R
Temperature
Membrane Proteins
Isothermal titration calorimetry
[SDV.SP]Life Sciences [q-bio]/Pharmaceutical sciences
Kinetics
030104 developmental biology
Rhoptry neck
Multiprotein Complexes
Biophysics
Anisotropy
Thermodynamics
lcsh:Q
[INFO.INFO-BI]Computer Science [cs]/Bioinformatics [q-bio.QM]
Peptides
Algorithms
Fluorescence anisotropy
[CHIM.CHEM]Chemical Sciences/Cheminformatics
Half-Life
Protein Binding
Research Article
Zdroj: PLoS ONE
PLoS ONE, Public Library of Science, 2016, 11 (1), pp.e0144764. ⟨10.1371/journal.pone.0144764⟩
PLoS ONE, Vol 11, Iss 1, p e0144764 (2016)
ISSN: 1932-6203
DOI: 10.1371/journal.pone.0144764⟩
Popis: Plasmodium falciparum is an obligate intracellular protozoan parasite that employs a highly sophisticated mechanism to access the protective environment of the host cells. Key to this mechanism is the formation of an electron dense ring at the parasite-host cell interface called the Moving Junction (MJ) through which the parasite invades. The MJ incorporates two key parasite components: the surface protein Apical Membrane Antigen 1 (AMA1) and its receptor, the Rhoptry Neck Protein (RON) complex, the latter one being targeted to the host cell membrane during invasion. Crystal structures of AMA1 have shown that a partially mobile loop, termed the DII loop, forms part of a deep groove in domain I and overlaps with the RON2 binding site. To investigate the mechanism by which the DII loop influences RON2 binding, we measured the kinetics of association and dissociation and binding equilibria of a PfRON2sp1 peptide with both PfAMA1 and an engineered form of PfAMA1 where the flexible region of the DII loop was replaced by a short Gly-Ser linker (ΔDII-PfAMA1). The reactions were tracked by fluorescence anisotropy as a function of temperature and concentration and globally fitted to acquire the rate constants and corresponding thermodynamic profiles. Our results indicate that both PfAMA1 constructs bound to the PfRON2sp1 peptide with the formation of one intermediate in a sequential reversible reaction: A↔B↔C. Consistent with Isothermal Titration Calorimetry measurements, final complex formation was enthalpically driven and slightly entropically unfavorable. Importantly, our experimental data shows that the DII loop lengthened the complex half-life time by 18-fold (900 s and 48 s at 25°C for Pf and ΔDII-Pf complex, respectively). The longer half-life of the Pf complex appeared to be driven by a slower dissociation process. These data highlight a new influential role for the DII loop in kinetically locking the functional binary complex to enable host cell invasion.
Databáze: OpenAIRE
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