Kinetic and computational analysis of the reversible inhibition of porcine pancreatic elastase: a structural and mechanistic approach. (3rd November 2016)

• Record Type: Journal Article
• Authors: Stergiou, Panagiota-Yiolanda; Foukis, Athanasios; Gkini, Olga A.; Bieth, Joseph G.; Papamichael, Emmanuel M.
• Is Part Of: Journal of enzyme inhibition and medicinal chemistry. Volume 31(2016:Jun.)Supplement 3
• Page Start: 131
• Page End: 139
• Publication Date: 2016-11-03
• Subjects: Inhibition mechanism -- molecular docking -- molecular dynamics -- proton inventories; Enzyme inhibitors -- Periodicals; Enzyme Inhibitors -- periodicals; Biochemistry -- periodicals; 572.7
• DOI: 10.1080/14756366.2016.1210137
• Languages: English
• ISSNs: 1475-6366

Abstract

Abstract: Structural and mechanistic insights were revealed for the reversible inhibition of Porcine Pancreatic Elastase (PPE); the kinetics of uninhibited and inhibited hydrolysis of substrate Suc-AAA-pNA was analyzed thoroughly. Additionally, the interactions between PPE and its inhibitor were studied by computational techniques. The uninhibited hydrolysis of Suc-AAA-pNA by PPE proceeds through a virtual transition state, involving an inferior physical and another dominating chemical step, where two stabilized reactant states precede the predominant acyl-enzyme. Different kinds of bonding with the PPE-backbone residues, including those of the catalytic triad, were found during the MD simulation of 5 ns, as key interactions favoring a higher stabilization of the best ranked complex PPE-CF3 C(O)-KA-NHPh-p-CF3 . The proton inventories of the inhibited hydrolysis of Suc-AAA-pNA by PPE, were ruled out the existence of any virtual transition state and thus they argue for a different mode of catalysis involving a structurally disturbed PPE molecule. Thereafter, a novel inhibition mechanism was suggested.