Details

Autor(en) / Beteiligte

• Klärner, Frank-Gerrit
• Schrader, Thomas
• Polkowska, Jolanta
• Bastkowski, Frank
• Talbiersky, Peter
• Campañá Kuchenbrandt, Mireia
• Schaller, Torsten
• de Groot, Herbert
• Kirsch, Michael

Titel

Effect of molecular clips and tweezers on enzymatic reactions by binding coenzymes and basic amino acids

Ist Teil von

• Pure and applied chemistry, 2010-04, Vol.82 (4), p.991-999

Ort / Verlag

Berlin: De Gruyter

Erscheinungsjahr

2010

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• The tetramethylene-bridged molecular tweezers bearing lithium methanephosphonate or dilithium phosphate substituents in the central benzene or naphthalene spacer-unit and the dimethylene-bridged clips containing naphthalene or anthracene sidewalls substituted by lithium methanephosphonate, dilithium phosphate, or sodium sulfate groups in the central benzene spacer-unit are water-soluble. The molecular clips having planar naphthalene sidewalls bind flat aromatic guest molecules preferentially, for example, the nicotinamide ring and/or the adenine-unit in the nucleotides NAD(P) , NMN, or AMP, whereas the benzene-spaced molecular tweezers with their bent sidewalls form stable host–guest complexes with the aliphatic side chains of basic amino acids such as lysine and argenine. The phosphonate-substituted tweezer and the clips having an extended central naphthalene spacer-unit or extended anthracene and benzo[k]fluoranthene sidewalls, respectively, form highly stable self-assembled dimers in aqueous solution, evidently due to non-classical hydrophobic interactions. The phosphate-substituted molecular clip containing naphthalene sidewalls inhibits the enzymatic, ADH-catalyzed ethanol oxidation by binding the cofactor NAD in a competitive reaction. Surprisingly, tweezer-bearing phosphate substituents in the central benzene spacer-unit are more efficient inhibitors for the ethanol oxidation than the correspondingly substituted naphthalene clip, even though the tweezer does not bind the cofactor NAD within the limits of detection. The phosphate-substituted naphthalene clip is, however, a highly efficient inhibitor of the enzymatic oxidation of glucose-6-phosphate (G6P) with NADP catalyzed by glucose-6-phosphate dehydrogenase (G6PD), whereas the phosphonate-substituted clip only functions as an inhibitor by forming a complex with the cofactor. Detailed kinetic, thermodynamic, and computational modeling studies provide insight into the mechanism of these novel enzyme inhibition reactions.