The effects of acrylamide on brain creatine kinase: Inhibition kinetics and computational docking simulation
ABSTRACT The occurrence of acrylamide is frequently observed in processed foods. Therefore, the harmful effects of acrylamide on metabolic enzymes are important to understand. We studied the inhibitory effects of acrylamide on the brain creatine kinase (CK-BB). We found that CK-BB was kinetically inactivated by acrylamide accompanied by the disruption of the hydrophobic surface. Acrylamide mainly interacted with the thiol (-SH) residue of CK-BB and resulted in alkylation. A computational docking simulation supported that acrylamide directly bound to the active site of CK-BB where cysteine and glycine residues interacted mainly. The inhibition kinetics combined with computational prediction can be useful in order to have insights into the mechanisms regarding environmentally hazardous factors at the molecular level.
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ABSTRACT: The regulation of enzymatic activity and unfolding studies of arginine kinase (AK) from various invertebrates have been the focus of investigation. To gain insight into the structural and folding mechanisms of AK from Euphausia superba (ESAK), we purified ESAK from muscle properly. The enzyme behaved as a monomeric protein with a molecular mass of about 40kD and had pH and temperature optima of 8.0 and 30°C, respectively. The Km(Arg) and Km(ATP) for the synthesis of phosphoarginine were 0.30 and 0.47mM, respectively, and kcat/Km(Arg) was 282.7 s(-1)/mM. A study of the inhibition kinetics of structural unfolding in the denaturant sodium dodecyl sulfate (SDS) was conducted. The results showed that ESAK was almost completely inactivated by 1.0mM SDS. The kinetics analyzed via time-interval measurements revealed that the inactivation was a first-order reaction, with the kinetic processes shifting from a monophase to biphase as SDS concentrations increased. Measurements of intrinsic and 1-anilinonaphthalene-8-sulfonate-binding fluorescence showed that SDS concentrations lower than 5mM did not induce conspicuous changes in tertiary structures, while higher concentrations of SDS exposed hydrophobic surfaces and induced conformational changes. These results confirmed that the active region of AK is more flexible than the overall enzyme molecule.International journal of biological macromolecules 03/2014; DOI:10.1016/j.ijbiomac.2014.03.044 · 2.37 Impact Factor
Computational Biology and Applied Bioinformatics, 09/2011; , ISBN: 978-953-307-629-4
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ABSTRACT: There is a great deal of interest in neurotrophin therapy to prevent neuronal degeneration. The present study aimed at synthesizing new functionalized indole derivatives with structures justifying neuroprotective activity using L-tryptophan (TRP) as starting material. The potential neuroprotective effect of these newly synthesized agents against acrylamide (ACR) induced neurotoxicity was investigated in adult female rats. The novel indole derivatives, indolylmethyl pyridine derivatives 9a,b, pyrimidinylindolyl propanone derivatives 12a-c, pyrazolylindolyl propanone derivatives 14a,b, and indolyl tetrazolopropanoic acid derivative 17 were synthesized and their chemical structures were confirmed by studying their analytical and spectral data. The administration of ACR [ip, 50mgkg(-1) body weight (b. wt.)] alone resulted in significant increase in brain malondialdehyde level (MDA) and lactate dehydrogenase (LDH) activity whereas it caused significant decrease in brain monoamines levels and antioxidant enzymes activity. Treatment with the indole derivatives 9b, 12c, 14a, and 17 (ip, 50mgkg(-1) b. wt.) prior to ACR produced neuroprotective activity with various intensities depending on the structure of each compound. Compound 17 in which the tetrazole ring was attached to the TRP moiety ranked as the strongest neuroprotective agent. All the tested compounds have been shown to possess antioxidant properties offering promising efficacy against oxidative stress induced by ACR administration.Bioorganic & medicinal chemistry 05/2011; 19(9):2966-74. DOI:10.1016/j.bmc.2011.03.031 · 2.82 Impact Factor