title: Comparison of three amyloid assembly inhibitors: the sugar scyllo-inositol, the polyphenol epigallocatechin gallate, and the molecular tweezer CLR01.
abstract: Many compounds have been tested as inhibitors or modulators of amyloid β-protein (Aβ) assembly in hope that they would lead to effective, disease-modifying therapy for Alzheimer's disease (AD). These compounds typically were either designed to break apart β-sheets or selected empirically. Two such compounds, the natural inositol derivative scyllo-inositol and the green-tea-derived flavonoid epigallocatechin gallate (EGCG), currently are in clinical trials. Similar to most of the compounds tested thus far, the mechanism of action of scyllo-inositol and EGCG is not understood. Recently, we discovered a novel family of assembly modulators, Lys-specific molecular tweezers, which act by binding specifically to Lys residues and modulate the self-assembly of amyloid proteins, including Aβ, into formation of nontoxic oligomers by a process-specific mechanism (Sinha, S., Lopes, D. H., Du, Z., Pang, E. S., Shanmugam, A., Lomakin, A., Talbiersky, P., Tennstaedt, A., McDaniel, K., Bakshi, R., Kuo, P. Y., Ehrmann, M., Benedek, G. B., Loo, J. A., Klarner, F. G., Schrader, T., Wang, C., and Bitan, G. (2011) Lysine-specific molecular tweezers are broad-spectrum inhibitors of assembly and toxicity of amyloid proteins. J. Am. Chem. Soc.133, 16958-16969). Here, we compared side-by-side the capability of scyllo-inositol, EGCG, and the molecular tweezer CLR01 to inhibit Aβ aggregation and toxicity. We found that EGCG and CLR01 had comparable activity whereas scyllo-inositol was a weaker inhibitor. Exploration of the binding of EGCG and CLR01 to Aβ using heteronuclear solution-state NMR showed that whereas CLR01 bound to the two Lys and single Arg residues in Aβ monomers, only weak, nonspecific binding was detected for EGCG, leaving the binding mode of the latter unresolved.
authors.affiliation: Department of Neurology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California, USA.
authors.forename: Sharmistha
authors.initials: S
authors.lastname: Sinha
authors.forename: Zhenming
authors.initials: Z
authors.lastname: Du
authors.forename: Panchanan
authors.initials: P
authors.lastname: Maiti
authors.forename: Frank-Gerrit
authors.initials: FG
authors.lastname: Klärner
authors.forename: Thomas
authors.initials: T
authors.lastname: Schrader
authors.forename: Chunyu
authors.initials: C
authors.lastname: Wang
authors.forename: Gal
authors.initials: G
authors.lastname: Bitan
mesh_terms: D016229:Amyloid beta-Peptides / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D001952:Bridged-Ring Compounds / Q000737:chemistry* / Q000494:pharmacology; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D007294:Inositol / Q000737:chemistry* / Q000494:pharmacology*; D010755:Organophosphates / Q000737:chemistry* / Q000494:pharmacology; D010446:Peptide Fragments / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000378:metabolism; D059808:Polyphenols / Q000737:chemistry / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D016229:Amyloid beta-Peptides; D001952:Bridged-Ring Compounds; C583031:CLR01 compound; D010755:Organophosphates; D010446:Peptide Fragments; D059808:Polyphenols; C075222:amyloid beta-protein (1-42); C009217:scyllitol; D007294:Inositol; D002392:Catechin; C045651:epigallocatechin gallate