Wen-Jing Zhu

Shandong Agricultural University, China

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Publications (4)10.13 Total impact

  • Hua-Rong Wang · Wen-Jing Zhu · Xiao-yun Wang
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    ABSTRACT: Arginine kinase plays a vital role in invertebrate homeostasis by buffering ATP concentrations. Arginine kinase might serve as a target for environmentally friendly insect-selective pesticides, because it differs notably from its counterpart in vertebrates, creatine kinase. In this study, two members of the flavonoid family, quercetin (QU) and luteolin (LU), were identified as novel noncompetitive inhibitors of locust arginine kinase. They were found to have inhibition parameters (K(i)) of 11.2 and 23.9 μM, respectively. By comparing changes in the activity and intrinsic fluorescence of AK, the inhibition mechanisms of these flavonoids were found to involve binding to Trp residues in the active site. This was determined by examination of the static quenching parameter K(sv). The main binding forces between flavonoids and AK were found to be hydrophobic based on the thermodynamic parameters of changes in enthalpy (ΔH), entropy (ΔS), and free energy (ΔG) and on docking simulation results. Molecular docking analyses also suggested that flavonoids could bind to the active site of AK and were close to the Trp 221 in active site. Molecular simulation results mimic the experimental results, indicated that QU had a lower binding energy and a stronger inhibitory effect on AK than LU, suggesting that the extra hydroxyl group in QU might increase binding ability.
    No preview · Article · Aug 2011 · International journal of biological macromolecules
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    ABSTRACT: Arginine kinase (AK; EC is a key enzyme in the cellular energy metabolism of insects. Screening on potential effective inhibitors of AK may provide a pathway for novel, environmentally friendly insecticides. The results in this study indicated that rutin, as a noncompetitive inhibitor, interacts with AK mainly by a hydrophobic force forming an intermolecular complex with AK, which is according to the thermodynamic parameters obtained. Using a flexible docking method (AutoDock) the interaction between rutin and AK were further analyzed, which suggested in order to screen effective inhibitors, flexible active sites of AK (Ser63, Gly64, Val65, Tyr68) should be taken in account.
    Preview · Article · Dec 2008 · International journal of biological macromolecules
  • Qing-Yun Wu · Feng Li · Wen-Jing Zhu · Xiao-Yun Wang
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    ABSTRACT: Arginine kinase (AK) is a phosphotransferase that plays a critical role in energy metabolism in invertebrates. The gene encoding Locusta migratoria manilensis AK was cloned and expressed in Escherichia coli by two prokaryotic expression plasmids, pET-30a and pET-28a. The recombinant protein was expressed as inclusion bodies using pET-30a. After denaturation, the recombinant AK was successfully renatured and confirmed to be enzymatically active. Addition of Tween-20 and SDS to the dilution system led to higher renaturation efficiency. Using another expression plasmid, pET-28a, and changing the expression conditions resulted in a soluble and functional form of AK, which was purified by an improved method using Sephadex G-75 chromotography to a final yield of 358 mg L(-1) of LB medium. Some parameters for the renatured and soluble forms of AK, including Km, Kd, specific activity, electrophoretic mobility and isoelectric focusing, were identical with those of AK obtained directly from L. migratoria manilensis leg muscle. Comparison of kinetic constants with those of AKs from other sources indicated that L. migratoria manilensis AKs have the highest kcat and stronger synergistic substrate binding. The first report of a concise purification method enables the enzyme to be prepared in large quantities. This research should enable further detailed investigations of the enzymatic mechanism by site directed mutagenesis techniques.
    No preview · Article · Jan 2008 · Comparative Biochemistry and Physiology Part B Biochemistry and Molecular Biology
  • Wen-Jing Zhu · Miao Li · Xiao-Yun Wang
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    ABSTRACT: Chemical modification was used to elucidate the essential amino acids in the catalytic activity of arginine kinase (AK) from Migratoria manilensis. Among six cysteine (Cys) residues only one Cys residue was determined to be essential in the active site by Tsou's method. Furthermore, the AK modified by DTNB can be fully reactivated by dithiothreitol (DTT) in a monophasic kinetic course. At the same time, this reactivation can be slowed down in the presence of ATP, suggesting that the essential Cys is located near the ATP binding site. The ionizing groups at the AK active site were studied and the standard dissociation enthalpy (DeltaH degrees ) was 12.38kcal/mol, showing that the dissociation group may be the guanidino of arginine (Arg). Using the specific chemical modifier phenylglyoxal (PG) demonstrated that only one Arg, located near the ATP binding site, is essential for the activity of AK.
    No preview · Article · Jan 2008 · International Journal of Biological Macromolecules