• BMB Reports
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• v.50 no.8
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• pp.391-392
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• 2017

Overexpression of mammalian 2-Cys peroxiredoxin (Prx) enzymes is observed in most cancer tissues. Nevertheless, their specific roles in colorectal cancer (CRC) progression has yet to be fully elucidated. Here, a novel molecular mechanism by which PrxII/Tankyrase (TNKS) interaction mediates survival of adenomatous polyposis coli (APC)-mutant CRC cells was explored. In mice with an inactivating APC mutation, a model of spontaneous intestinal tumorigenesis, deletion of PrxII reduced intestinal adenomatous polyposis and thereby increased survival. In APC-mutant human CRC cells, PrxII depletion hindered PARP-dependent Axin1 degradation through TNKS inactivation. $H_2O_2-sensitive$ Cys residues in the zinc-binding domain of TNKS1 was found to be crucial for PARsylation activity. Mechanistically, direct binding of PrxII to ARC4/5 domains of TNKS conferred vital redox protection against oxidative inactivation. As a proof-of-concept experiment, a chemical compound targeting PrxII inhibited the growth of tumors xenografted with APC-mutation-positive CRC cells. Collectively, the results provide evidence revealing a novel redox mechanism for regulating TNKS activity such that physical interaction between PrxII and TNKS promoted survival of APC-mutant colorectal cancer cells by PrxII-dependent antioxidant shielding.

• BMB Reports
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• v.29 no.2
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• pp.169-174
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• 1996

Yeast cytochrome c (cyt c) was modified at cysteine-102 with a thiol-specific spin label and its interaction with liposomes containing acidic phospholipids was studied by electron paramagnetic resonance (EPR) spectroscopy. Association of cyt c with liposomes resulted in a significant reduction in the mobility of the spin label and a fraction of cyt c even seemed to be immobilized. Based on a large spectral change upon binding and the proximity of the spin-label to lysine-86 and -87, we propose these two residues to be the potential binding site at neutral pH. The interaction is electrostatic in nature because the spectral changes were reversed by addition of anions. Dissociation of the bound cyt c by anions, however, became less effective as the lipid/protein ratio increased. This suggests a repulsive lateral interaction among the bound cyt c. Unlabeled cyt c molecules added to preformed cyt c-liposome complex displaced the bound (spin labeled) cyt c and the process was competitive and reversible.

• BMB Reports
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• v.28 no.2
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• pp.100-106
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• 1995

S-adenosylmethionine (SAM) synthetase was purified to homogeneity from soybean (Glycine max) axes. The enzyme was purified 216-fold with a 1.5% yield by ammonium sulfate fractionation, acetone fractionation, ion exchange chromatography with DEAE-sephacel, gel filtration with Sephacryl S-300, and afffinity chromatography with ATP-agarose. The enzyme activity reached a maximum 3 days after germination. SAM synthetase had a subunit molecular weight of 57,000 daltons from a silver stained single band on SDS-PAGE. The molecular weight of the enzyme was 110,000 daltons from Sephacryl S-300 gel filtration. The enzyme was composed of two identical subunits. The $K_m$ values of the enzyme for L-methionine and ATP were 1.81 and 1.53 mM, respectively. The enzymatic activity was not affected by polyamines, agmatine, or SAM analogues, but was inhibited by SAM. The inhibition pattern was showed non-competitive for L-methionine and uncompetitive for ATP. The activity of SAM synthetase was inhibited by thiol-blocking reagents. The enzyme was induced by treatment with $10^{-3}$ M putrescine at germination. Experimental data revealed a possible novel regulation mechanism of polyamine biosynthesis through several endogenous intermediates.

• BMB Reports
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• v.30 no.2
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• pp.132-137
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• 1997

In order to compare molecular structure, malonate decarboxylases from Acinetobacter calcoaceticus, Pseudomonas fluorescens, and Pseudomonas putida aerobically grown on malonate, were purified by the method employing streptomycin sulfate treatment, chromatography with PBE 94 and ${\omega}-aminohexyl$ agarose. Molecular masses were estimated to be 185, 200, and 200 kDa, respectively. All malonate decarboxylases were multimeric enzymes consisting of four different subunits, $2{\alpha},\;1{\beta},\;1{\gamma},\;and\;1{\delta}$. The molecular masses of the Pseudomonas enzyme subunits were $65({\alpha})$, $33({\beta})$, $30({\gamma})$, and $11kDa({\delta})$; which are very similar to those, $65({\alpha})$, $32({\beta})$, $25({\gamma})$, and $11kDa({\delta})$ of Acinetobacter enzyme. The ${\delta}-subunit$ of the active form of the enzymes was acetylated. The acetyl group may form a thioester bond with the thiol group of the prosthetic group covalently linked to the enzyme. It suggests that such molecular organization is common in all malonate decarboxylases.

• Biomolecules & Therapeutics
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• v.12 no.2
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• pp.92-100
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• 2004

Effect of the depletion or oxidation of GSH on mitomycin c (MMC)-induced mitochondrial damage and cell death was assessed in small cell lung cancer (SCLC) cells. MMC induced cell death and the decrease in the GSH contents in SCLC cells, which were inhibited by z-LEHD.fmk (a cell permeable inhibitor of caspase-9), z-DQMD.fmk (a cell permeable inhibitor of caspase-3) and thiol compound, N-acetylcysteine. MMC caused nuclear damage, release of cytochrome c and activation of caspase-3, which were reduced by N-acetylcysteine. The depletion of GSH due to L-butionine-sulfoximine enhanced the MMC-induced cell death and formation of reactive oxygen species in SCLC cells, whereas the oxidation of GSH due to diamide or $NH_2Cl$ did not affect cytotoxicity of MMC. The results show that MMC may cause cell death in SCLC cells by inducing mitochondrial dysfunction, leading to activation of caspase-9 and -3. The MMC-induced change in the mitochondrial membrane permeability, followed by cell death, in SCLC cells may be significantly enhanced by the depletion of GSH. In contrast, the oxidation of GSH may not affect cytotoxicity of MMC.

• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.1
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• pp.63-68
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• 2002

A cDNA encoding a putative member of cathepsin B of the thiol pretense superfamily was cloned from a cDNA library of the mulberry longicorn beetle, Apriona germari. Sequence analysis of the cDNA encoding the cathepsin B of A. germari (AgCatB) revealed that the 972 bp cDNA has an open reading frame of 324 amino acid residues. The deduced protein sequence of the AgCatB showed high homology with cathepsin B of the insects, Bombyx mori (47.3% amino acid identity), Helicoverpa armigera (46.6%) and Sarcophaga peregrina (45.6%), and the lowest homology with Aedes aegypti (33.2%). The AgCatB contains six disulfate bonds typical for cysteine pretenses. The three amino acid positions Cys-109, His-267, and Asn-287 which are conserved, active sites characteristic for cathepsin B, were also found. Phylogenetic analysis further confirmed that the AgCatB has a close relationship with that of B. mori, H. armigera and S. peregrina.

• International Journal of Industrial Entomology and Biomaterials
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• v.37 no.1
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• pp.15-20
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• 2018

Most proteins produced in the endoplasmic reticulum (ER) of eukaryotic cells fold via disulfide formation (oxidative folding). Oxidative folding is catalyzed by protein disulfide isomerase (PDI) and PDI-related ER protein thiol disulfide oxidoreductases (ER oxidoreductases). In yeast and mammals, ER oxidoreductin-1s (ERO1s) supply oxidizing equivalent to the active centers of PDI. We previously identified and characterized the ERO1 of Bombyx mori (bERO1) as a thioredoxin-like protein that shares primary sequence homology with other ERO1s. Here we compare the reactivation of inactivated rRNase and sRNase by bERO1, and show that bERO1 and bPDI cooperatively refold denatured RNase A. This is the first result suggesting that bERO1 plays an essential role in ER quality control through the combined activities of bERO1 and bPDI as a catalyst of protein folding in the ER and sustaining cellular redox homeostasis.

• Journal of Microbiology and Biotechnology
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• v.16 no.7
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• pp.1047-1052
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• 2006

A bile salt hydrolase (BSH) was purified from Lactobacillus plantarum CK 102 and its enzymatic properties were characterized. This enzyme was successfully purified using ion-exchange chromatography with Q-Excellose and hydrophobic interaction chromatography with Butyl-Excellose. The purified enzyme showed a single protein band of 37 kDa by SDS-polyacrylamide gel electrophoresis, which was similar to the molecular weight of known BSHs. The amino acid sequence of GLGLPGDLSSMSR, determined by MALDI-TOF, was identical to that of BSH of L. plantarum WCFS1. Although this BSH hydrolyzed all of the six major human bile salts, glycine-conjugated bile acid was the best substrate, based on its specificity and $K_{m}$ value. Among the various substrates, the purified enzyme maximally hydrolyzed glycocholate with apparent $K_{m}$ and $V_{max}$ values of 0.5 mM and 94 nmol/min/mg, respectively. The optimal pH of the enzyme ranged from 5.8 to 6.3. This enzyme was strongly inhibited by thiol enzyme inhibitors such as iodoacetate and periodic acid.

• Journal of the Korean Applied Science and Technology
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• v.23 no.4
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• pp.355-361
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• 2006

[1,2,4]-Triazole derivatives were synthesized by 5 steps. Benzimidazole was refluxed with ethyl chloroacetate to give 1H-benzimidazole-acetic acid ethyl ester (1) over 52% yield. Ester (1) was refluxed with hydrazine hydrate in the presence of ethanol to afford 1H-benzimidazole-1-acetic acid, hydrazide (2). 5-Benzoimidazol-1-ylmethyl-4H-[1,2,4]triazole-3-thiol (4) was made via coupling of compound (2) with methyl isothiocyanate, followed by cyclization of 1H-benzimidazole-1-acetic acid, 2-[(methylamino) thioxomethyl]hydrazide (3) on reflux, and finally the target compounds (6a-6v) were synthesized by general substitution reaction. Compounds (6a-6v) were screened for T-type calcium channel blocker using the fluorescence assay by FDSS6000. All compounds (6a-6v) did not show better activities than control compound, mibefradil.

• Journal of the Korean Applied Science and Technology
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• v.24 no.2
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• pp.109-116
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• 2007

2-Chlorobenzoyl hydrazine refluxed with benzoyl isothiocyanate and phenyl isothiocyanate in ethanol for 3 hours to give benzamide derivative (1) and anilinederivative (2) on yield of 71%and 95%, respectively. Benzamide derivative (1) reacted with ethanolic sodium hydroxide on reflux to afford cyclization product (3), followed by general substitution reaction of two steps to give acetamide (5), and derivatived acetamides 7a-7k, while aniline derivative (2) reacted with ethanolic sodium hydroxide on reflux to afford another cyclization product (4). Thiol (4) reacted with N-phenyl chloroacetamide in the presence of potassim carbonate to give acetamide derivative (6). Compounds 1-7kwere evaluated for their growth inhibition against five cancer cell lines, including human lung carcinoma (A-549), human prostate cancer (DU145), human colon adenocarcinoma (HT-29), human malignant melanoma (SK-MEL-2) and human ovary malignant ascites (SK-OV-3) with sulforhodamine B (SRB) assay. All compounds (1-7k) showed low inhibition activities under 50% on 100M concentration.