Allosteric inhibition of carnosinase (CN1) by inducing a conformational shift. (1st January 2017)

• Record Type: Journal Article
• Authors: Peters, Verena; Schmitt, Claus P.; Weigand, Tim; Klingbeil, Kristina; Thiel, Christian; van den Berg, Antje; Calabrese, Vittorio; Nawroth, Peter; Fleming, Thomas; Forsberg, Elisabete; Wagner, Andreas H.; Hecker, Markus; Vistoli, Giulio
• Is Part Of: Journal of enzyme inhibition and medicinal chemistry. Volume 32:Number 1(2017)
• Page Start: 1102
• Page End: 1110
• Publication Date: 2017-01-01
• Subjects: Carnosinase 1 activity -- CN1 -- allosteric inhibition -- glutathione -- N-acetylcysteine -- diabetes; Enzyme inhibitors -- Periodicals; Enzyme Inhibitors -- periodicals; Biochemistry -- periodicals; 572.7
• DOI: 10.1080/14756366.2017.1355793
• Languages: English
• ISSNs: 1475-6366

Abstract

Abstract: In humans, low serum carnosinase (CN1) activity protects patients with type 2 diabetes from diabetic nephropathy. We now characterized the interaction of thiol-containing compounds with CN1 cysteine residue at position 102, which is important for CN1 activity. Reduced glutathione (GSH), N-acetylcysteine and cysteine (3.2 ± 0.4, 2.0 ± 0.3, 1.6 ± 0.2 µmol/mg/h/mM; p < .05) lowered dose-dependently recombinant CN1 (rCN1) efficiency (5.2 ± 0.2 µmol/mg/h/mM) and normalized increased CN1 activity renal tissue samples of diabetic mice. Inhibition was allosteric. Substitution of rCN1 cysteine residues at position 102 (Mut1 C102S ) and 229 (Mut2 C229S ) revealed that only cysteine-102 is influenced by cysteinylation. Molecular dynamic simulation confirmed a conformational rearrangement of negatively charged residues surrounding the zinc ions causing a partial shift of the carnosine ammonium head and resulting in a less effective pose of the substrate within the catalytic cavity and decreased activity. Cysteine-compounds influence the dynamic behaviour of CN1 and therefore present a promising option for the treatment of diabetes.