Title: Inhibitory Activity of Quercetin 3-O-Arabinofuranoside and 2-Oxopomolic Acid Derived from Malus domestica on Soluble Epoxide Hydrolase Cho IS, Kim JH, Lin Y, Su XD, Kang JS, Yang SY, Kim YH Ref: Molecules, 25:, 2020 : PubMed
Flavonoids and triterpenoids were revealed to be the potential inhibitors on soluble epoxide hydrolase (sEH). The aim of this study is to reveal sEH inhibitors from Fuji apples. A flavonoid and three triterpenoids derived from the fruit of Malus domestica were identified as quercetin-3-O-arabinoside (1), ursolic acid (2), corosolic acid (3), and 2-oxopomolic acid (4). They had half-maximal inhibitory concentration of the inhibitors (IC(50)) values of 39.3 +/- 3.4, 84.5 +/- 9.5, 51.3 +/- 4.9, and 11.4 +/- 2.7 muM, respectively, on sEH. The inhibitors bound to allosteric sites of enzymes in mixed (1) and noncompetitive modes (2-4). Molecular simulations were carried out for inhibitors 1 and 4 to calculate the binding force of ligands to receptors. The inhibitors bound to the left (1) and right (4) pockets next to the enzyme's active site. Based on analyses of their molecular docking and dynamics, it was shown that inhibitors 1 and 4 can stably bind sEH at 1 bar and 300 K. Finally, inhibitors 1 and 4 are promising candidates for further studies using cell-based assays and in vivo cardiovascular tests.
Title: Inhibition potential of phenolic constituents from the aerial parts of Tetrastigma hemsleyanum against soluble epoxide hydrolase and nitric oxide synthase Wang CY, Lee S, Jang HJ, Su XD, Wang HS, Kim YH, Yang SY Ref: J Enzyme Inhib Med Chem, 34:753, 2019 : PubMed
The aerial parts of Tetrastigma hemsleyanum (APTH) have been used as a functional tea in China. The purpose of the current study was to identify the bioactive constituents with inhibitory activity against soluble epoxide hydrolase (sEH) and inducible nitric oxide synthase (iNOS), which are jointly considered potential therapeutic targets for vascular system diseases. In the present study, 39 compounds (1-39) were isolated from the APTH. Among them, compounds 8, 10, 12, 16, 17, 19, and 32 displayed potential activities, with IC50 values ranging from 4.5 to 9.5 microM, respectively, and all in non-competitive inhibition mode. Compounds 5, 10, 12, 19, and 32 displayed potent iNOS inhibitory effects, with IC50 values ranging from 15.6 to 47.3 microM. The results obtained in this work contribute to a better understanding of the pharmacological activities of T. hemsleyanum and its potential application as a functional food.
Title: Structural and functional characterization of a novel alpha/beta hydrolase from cariogenic pathogen Streptococcus mutans Wang Z, Li L, Su XD Ref: Proteins, 82:695, 2014 : PubMed
The protein Smu.1393c from Streptococcus mutans is annotated as a putative alpha/beta hydrolase, but it has low sequence identity to the structure-known alpha/beta hydrolases. Here we present the crystal structure of Smu.1393c at 2.0 A resolution. Smu.1393c has a fully open alkaline substrate pocket, whose conformation is unique among other similar hydrolase structures. Three residues, Ser101, His251, and Glu125, were identified as the active center of Smu.1393c. By screening a series of artificial hydrolase substrates, we demonstrated Smu.1393c had low carboxylesterase activity towards short-chain carboxyl esters, which provided a clue for exploring the in vivo function of Smu.1393c. Proteins 2014; 82:695-700. (c) 2013 Wiley Periodicals, Inc.
Title: Purification, crystallization and preliminary X-ray analysis of a maize cytokinin glucoside specific beta-glucosidase Vevodova J, Marek J, Zouhar J, Brzobohaty B, Su XD Ref: Acta Crystallographica D Biol Crystallogr, 57:140, 2001 : PubMed
Zm-p60.1, a cytokinin glucoside specific beta-glucosidase from maize, is a key enzyme involved in plant development and growth. It has been overexpressed in soluble form from Escherichia coli with a His tag at its N-terminus. The recombinant protein has been purified and crystallized at room temperature using PEG 4000 as the main precipitant. At least three crystal forms have been observed from very similar growth conditions. A flash-annealed monoclinic crystal diffracted to high resolution (beyond 2 A) with space group P2(1) and unit-cell parameters a = 55.66, b = 110.72, c = 72.94 A, beta = 92.10 degrees. The asymmetric unit is estimated and confirmed by molecular-replacement solution to contain one Zm-p60.1 dimer, giving a crystal volume per protein mass (V(M)) of 1.89 A(3) Da(-1) and a solvent content of 35%.
