S-methyl-L-cysteine sulfoxide (SMCO) is a non-protein sulfur-containing amino acid with a variety of functions. There are few reports on the enzymes catalyzing the biosynthesis of SMCO from S-methyl-L-cysteine (SMC). In this study, the flavin-containing monooxygenase gene derived from Schizosaccharomyces pombe (spfmo) was heterologously expressed in Escherichia coli BL21(DE3) and the enzymatic properties of the expressed protein were analyzed. The optimum catalytic conditions of the recombinant SpFMO were 30 ℃ and pH 8.0, under which the enzyme activity reached 72.77 U/g. An appropriate amount of Mg²⁺ improved the enzyme activity. The enzyme kinetic analysis showed that the K_m and k_cat/K_m of SpFMO on the substrate SMC were 23.89 μmol/L and 61.71 L/(min·mmol), respectively. Under the optimal reaction conditions, the yield of SMCO synthesized from SMC catalyzed by SpFMO was 12.31% within 9 h. This study provides reference for the enzymatic synthesis of SMCO.
Schizosaccharomyces/genetics* ; Escherichia coli/metabolism* ; Recombinant Proteins/metabolism* ; Cysteine/biosynthesis* ; Mixed Function Oxygenases/metabolism* ; Schizosaccharomyces pombe Proteins/metabolism* ; Oxygenases/metabolism* ; Kinetics

Bucillamine is used for the treatment of rheumatoid arthritis. This study investigated the protective effects of bucillamine against cisplatin-induced damage in auditory cells, the organ of Corti from postnatal rats (P2) and adult Balb/C mice. Cisplatin increases the catalytic activity of caspase-3 and caspase-8 proteases and the production of free radicals, which were significantly suppressed by pretreatment with bucillamine. Bucillamine induces the intranuclear translocation of Nrf2 and thereby increases the expression of gamma-glutamylcysteine synthetase (gamma-GCS) and glutathione synthetase (GSS), which further induces intracellular antioxidant glutathione (GSH), heme oxygenase 1 (HO-1) and superoxide dismutase 2 (SOD2). However, knockdown studies of HO-1 and SOD2 suggest that the protective effect of bucillamine against cisplatin is independent of the enzymatic activity of HO-1 and SOD. Furthermore, pretreatment with bucillamine protects sensory hair cells on organ of Corti explants from cisplatin-induced cytotoxicity concomitantly with inhibition of caspase-3 activation. The auditory-brainstem-evoked response of cisplatin-injected mice shows marked increases in hearing threshold shifts, which was markedly suppressed by pretreatment with bucillamine in vivo. Taken together, bucillamine protects sensory hair cells from cisplatin through a scavenging effect on itself, as well as the induction of intracellular GSH.
Animals ; Antioxidants/*metabolism/*pharmacology ; Apoptosis/drug effects ; Caspase 3/metabolism ; Caspase 8/metabolism ; Cell Line ; Cisplatin/*toxicity ; Cysteine/*analogs & derivatives/pharmacology ; Gene Expression Regulation/*drug effects ; Gene Knockdown Techniques ; Glutathione/*metabolism ; Heme Oxygenase-1/genetics ; Intracellular Space/metabolism ; Male ; Metabolic Detoxication, Phase II/genetics ; Mice ; NF-E2-Related Factor 2/genetics ; Nitric Oxide/biosynthesis ; Organ of Corti/*drug effects/*metabolism ; RNA Interference ; Rats ; Reactive Oxygen Species/metabolism ; Superoxide Dismutase/genetics

Peptide cyclization, a pivotal approach to modifying linear precursors of proteins and pepticles, has been used to enhance their biological activities and serum stabilities. Recently, sortase A (SrtA) from Staphyloccus aureus becomes a promising new technology for efficiently incorporating site specific modifications into proteins, conjugating the cell surface and cyclizing the linear peptides. In this study, we constructed two recombinant expression systems, one with chitin binding domain and the other with six-histidine tag and chitin binding domain on the N-terminal of SrtA, separately. The results of enzymatic kinetics indicate that the two recombinant tags do not impair the transpeptidase activity of SrtA compared with the standard reaction reported under the same reaction condition. The two synthesized peptides with N-ternimal three glycines and C-terminal penta-amino acid motif, LPETG, were cyclized using immobilized and recycled SrtA. The SrtA-based cyclization promises to represent a simple method for easy and efficient enzymatic synthesis of large cyclic peptides.
Aminoacyltransferases ; metabolism ; Bacterial Proteins ; metabolism ; Cyclization ; Cysteine Endopeptidases ; metabolism ; Enzymes, Immobilized ; metabolism ; Kinetics ; Peptides ; metabolism ; Peptides, Cyclic ; biosynthesis ; Staphylococcus aureus ; enzymology

Acetates ; administration & dosage ; therapeutic use ; Asthma ; drug therapy ; etiology ; metabolism ; Bronchiolitis, Viral ; drug therapy ; Cysteine ; metabolism ; Humans ; Infant ; Infant, Newborn ; Leukotriene Antagonists ; administration & dosage ; therapeutic use ; Leukotrienes ; biosynthesis ; Nasopharynx ; secretion ; Quinolines ; administration & dosage ; therapeutic use ; Respiratory Syncytial Virus Infections ; drug therapy ; metabolism ; virology ; Risk Factors

In order to study whether cysteine-rich 61 protein (cyr61) is involved in the pathogenesis of asthma and its relation to airway inflammation, the effect of dexamethasone (Dxm) on the expression of cyr61 in the lung tissues of asthmatic mice was investigated. Forty BALB/c mice were divided into asthma group (n=15), control group (n=10) and Dxm group (n=15). The asthma group was sensitized and challenged by ovalbumin (OVA). The mice in Dxm group were intraperitoneally administered with Dxm after OVA challenge. The expression of cyr61 in the lung tissues was detected by using immunohistochemistry, and that of eotaxin protein in the bronchoalveolar lavage fluid (BALF) by using enzyme-linked immunosorbent assay (ELISA). The number of inflammatory cells in BALF was also analyzed. The results showed that the cyr61 expression was highest in asthma group (P<0.05), followed by Dxm group (P<0.05) and control group. The cyr61 had a positive correlation with the total nucleated cells (r=0.867, P<0.05), especially eosinophils (r=0.856, P<0.05), and eotaxin level (r=0.983, P<0.05) in the BALF. Our findings suggested that cyr61 is expressed in airway epithelial cells and has a positive correlation with eotaxin and number of airway infiltrating eosinophils.
Animals ; Anti-Inflammatory Agents ; administration & dosage ; pharmacology ; Asthma ; chemically induced ; drug therapy ; metabolism ; Bronchoalveolar Lavage Fluid ; chemistry ; cytology ; Chemokines, CC ; metabolism ; Cysteine-Rich Protein 61 ; biosynthesis ; Dexamethasone ; administration & dosage ; pharmacology ; Enzyme-Linked Immunosorbent Assay ; Epithelial Cells ; drug effects ; metabolism ; pathology ; Female ; Immunohistochemistry ; Injections, Intraperitoneal ; Leukocyte Count ; Lung ; metabolism ; pathology ; Mice ; Mice, Inbred BALB C ; Neutrophils ; drug effects ; pathology ; Ovalbumin

The purpose of this paper is to establish sulfhydryl site-directed PEGylation method for lysostaphin and to evaluate effects of mutagenesis and modification of amino acid residue within putative linker on enzyme activity. On the basis of structural analysis of lysostaphin, amino acid 133-154 of tentative linker between the N-terminal and C-terminal domain were chosen as the candidate residues for site-directed mutagenesis to cysteine. Subsequently, sulfhydryl site-directed PEGylation was performed by reacting PEG-maleimide reagent with the newly introduced cysteine residue of the mutant lysostaphin. The Cys-mutant and PEG-modified proteins were both purified, and their enzymatic activity were further PEGylated lysostaphins. The mono-PEGylated lysostaphins were separated from unmodified lysostaphins through highly efficient one step method with Ni(2+)-NTA column chromatography. However, both Cys-mutant and PEGylated lysostaphin only retained partial activities of the wild-type enzyme. It suggests that sulfhydryl site-directed PEGylation modification of the tentative linker between the N-terminal and C-terminal domain may affect the catalytic activity of lysostaphin.
Anti-Infective Agents, Local ; chemistry ; metabolism ; Base Sequence ; Catalysis ; Cysteine ; chemistry ; genetics ; metabolism ; Escherichia coli ; genetics ; metabolism ; Lysostaphin ; biosynthesis ; chemistry ; metabolism ; Molecular Sequence Data ; Mutagenesis, Site-Directed ; Mutant Proteins ; chemistry ; metabolism ; Polyethylene Glycols ; chemistry ; Recombinant Proteins ; biosynthesis ; genetics ; metabolism ; Staphylococcus ; metabolism ; Sulfhydryl Reagents ; pharmacology

The aim of the study is to obtain an efficient expression of recombinant ubiquitin-like specific protease 1 (Ulp1) by gene engineering. We cloned the Ulp1p, active fragment (403 aa-621 aa) of Ulp1, from Saccharomyces cerevisia, and subcloned into pGEX/Rosetta (DE3) to form an expression plasmid, pGEX-Ulp1p-His6. In order to enhance the solubility of GST-Ulp1p-His6, we purified the fusion protein GST-Ulp1p-His6 by either glutathione S-transferase agarose or Ni-NTA resin chromatography, the purity was up to 98%. We utilized the protein to cleave the SUMO fusions, and the specific activity of GST-Ulp1p-His6 was 1.375 x 10(4) U/mg. This study showed that the recombinant protein GST-Ulp1p-His6 displayed high specificity and activity.
Cloning, Molecular ; Cysteine Endopeptidases ; biosynthesis ; genetics ; Escherichia coli ; genetics ; metabolism ; Fungal Proteins ; biosynthesis ; genetics ; Glutathione Transferase ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Saccharomyces cerevisiae ; enzymology ; Solubility

Uterine tumors are the most common type of gynecologic neoplasm. Uterine leiomyosarcoma (LMS) is rare, accounting for 2% to 5% of tumors of the uterine body. Uterine LMS develops more often in the muscle tissue layer of the uterine body than in the uterine cervix. The development of gynecologic tumors is often correlated with female hormone secretion; however, the development of uterine LMS is not substantially correlated with hormonal conditions, and the risk factors are not yet known. Radiographic evaluation combined with PET/CT can be useless in the diagnosis and surveillance of uterine LMS. Importantly, a diagnostic biomarker, which distinguishes malignant LMS and benign tumor leiomyoma (LMA) is yet to be established. Accordingly, it is necessary to analyze risk factors associated with uterine LMS in order to establish a method of treatment. LMP2-deficient mice spontaneously develop uterine LMS, with a disease prevalence of ∼40% by 14 months of age. It is therefore of interest whether human uterine LMS shows a loss of LMP2 expression. We found LMP2 expression is absent in human LMS, but present in human LMA. Therefore, defective LMP2 expression may be one of the risk factors for LMS. LMP2 is potentially a diagnostic biomarker for uterine LMS, and gene therapy with LMP2-encording DNA may be a new therapeutic approach.
Animals ; Biomarkers, Tumor ; biosynthesis ; genetics ; Cysteine Endopeptidases ; biosynthesis ; genetics ; Down-Regulation ; Female ; Gene Deletion ; Humans ; Interferon Regulatory Factor-1 ; biosynthesis ; genetics ; Leiomyoma ; metabolism ; Leiomyosarcoma ; diagnosis ; genetics ; metabolism ; Mice ; Mice, Knockout ; Proteasome Endopeptidase Complex ; metabolism ; Uterine Neoplasms ; diagnosis ; genetics ; metabolism

We cloned genes of four sentrin-specific protease (SENP), three small ubiquitin-like modifiers (SUMO), enhanced cyan fluorescent protein (ECFP) and yellow fluorescent protein (EYFP) by two-step PCR. Then we constructed expression vector B28 for SENP and B13 for ECFP-SUMO-EYFP. The recombinant plasmids were transformed into Escherichia coli BL21 and expression was induced by isopropyl beta-D-thiogalactoside, then recombinant proteins were purified by Ni-NTA agarose column ion-exchange chromatography. The proteins were analyzed with SDS-PAGE and identified with Western blotting. Except that SENP3 catalytic domain (SENP3C) truncated in the C termini and SENP5C expressed in inclusion body, others were expressed as soluble proteins. SDS-PAGE analysis showed that the relative molecular mass of these fusion proteins were consistent with theoretical ones, and the specificity of the fusion proteins were confirmed with Western blotting. The fusion proteins of SENP and ECFP-SUMO-EYFP can be successfully expressed in prokaryotic expression system. It lays the foundation for the fluorescence resonance energy transfer analysis.
Bacterial Proteins ; biosynthesis ; genetics ; Catalytic Domain ; Cysteine Endopeptidases ; biosynthesis ; genetics ; Endopeptidases ; biosynthesis ; genetics ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; Green Fluorescent Proteins ; biosynthesis ; genetics ; Humans ; Luminescent Proteins ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; SUMO-1 Protein ; biosynthesis ; genetics

According to the amino acids sequence of OC-IdeltaD86 gene and Escherichia coli codon usage, we synthesized this gene by overlap extension PCR method with 7 oligonucleotides DNA fragments. The PCR fragment was inserted into pGEM-T-easy vector and the recombined plasmid was named pGEM-T-OC-IdeltaD86. Two oligonucleotides into which the BamH I and Xho I sites were introduced were designed and synthesized based on pGEM-T-OC-IdeltaD86 and pet21b, and the PCR fragment into which the BamH I and Xho I sites were introduced was obtained. After digesting it with BamH I and Xho I, OC-IdeltaD86 gene was cloned into the corresponding sites of pet21b and obtained prokaryotic expression vector pet21b-OC-IdeltaD86. OC-IdeltaD86 gene was expressed in E. coli (BL21(DE3)plysS) after IPTG(Isopropyl beta-D-1-thiogalactopyranoside) inducement for 5 hours. The fusion protein of OC-IdeltaD86:6His gene accounted for 11.4% of total protein and 16.4% of soluble protein, which had been successfully purified by Ni-NTA and concentrated by PEG20000. This protein can effectively inhibit papain activity in vitro and may be used in anti-nematode research in vivo.
Cloning, Molecular ; Cystatins ; biosynthesis ; genetics ; Cysteine Endopeptidases ; metabolism ; Cysteine Proteinase Inhibitors ; genetics ; Escherichia coli ; genetics ; metabolism ; Genes, Plant ; genetics ; Mutation ; Oligonucleotides ; chemical synthesis ; genetics ; Oryza ; genetics ; Papain ; antagonists & inhibitors ; Prokaryotic Cells ; metabolism ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; metabolism