Deciphering the kinetic binding mechanism of dimeric ligands, using a potent plasma-stable dimeric inhibitor of postsynaptic density protein-95 as an example
2010 (English)In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 285, no 36, 28252-28260 p.Article in journal (Refereed) Published
Dimeric ligands can be potent inhibitors of protein-protein or enzyme-substrate interactions. They have increased affinity and specificity towards their targets due to their ability to bind simultaneously to two binding sites and are therefore very attractive in drug design. However, few studies have addressed the kinetic mechanism of interaction of such bivalent ligands. We have investigated the binding interaction of a recently identified potent plasma-stable dimeric pentapeptide of PDZ1-2 of PSD-95 using protein engineering in combination with fluorescence polarisation, isothermal titration calorimetry and stopped-flow fluorimetry. Our experiments demonstrate that binding occurs via a two-step process, where an initial binding to either one of the two PDZ domains is followed by an intramolecular step, which produces the bidentate complex. We have determined all rate constants involved in the binding reaction and we also find evidence for a conformational transition of the complex. Our data demonstrate the importance of a slow dissociation for a successful dimeric ligand, but also highlight the possibility of optimizing the intramolecular association rate. The results may therefore aid the design of dimeric inhibitors in general.
Place, publisher, year, edition, pages
2010. Vol. 285, no 36, 28252-28260 p.
protein-protein interactions, dimeric ligand, PDZ, conformational change, inhibitors
Other Basic Medicine
Research subject Biochemistry
IdentifiersURN: urn:nbn:se:uu:diva-126083DOI: 10.1074/jbc.M110.124040ISI: 000281404100068PubMedID: 20576616OAI: oai:DiVA.org:uu-126083DiVA: diva2:321843