Terpenoid indole (TIAs) and β-carboline alkaloids (BCAs), such as suppressant reserpine, vasodilatory yohimbine, and antimalarial quinine, are natural compounds derived from strictosidine. These compounds can exert powerful pharmacological effects but be obtained from limited source in nature. the whole biosynthetic pathway of TIAs and BCAs, The Pictet-Spengler reaction catalyzed by strictosidine synthase (STR; EC: 4.3.3.2) is the rate-limiting step. Therefore, it is necessary to investigate their biosynthesis pathways, especially the role of STR, and related findings will support the biosynthetic generation of natural and unnatural compounds. This review summarizes the latest studies concerning the function of STR in TIA and BCA biosynthesis, and illustrates the compounds derived from strictosidine. The substrate specificity of STR based on its structure is also summarized. Proteins that contain six-bladed four-stranded β-propeller folds in many organisms, other than plants, are listed. The presence of these folds may lead to similar functions among organisms. The expression of STR gene can greatly influence the production of many compounds. STR is mainly applied to product various valuable drugs in plant cell suspension culture and biosynthesis in other carriers.
Alkaloids/biosynthesis* ; Carbolines/metabolism* ; Carbon-Nitrogen Lyases ; Indoles/metabolism* ; Terpenes/metabolism*

Indigo and indigo-like pigments are widely used in the industry of textile, food and medicine. Now people pays more and more attention to developing an alternative method of indigo production which is "environment-friendy", especially microbial biosynthesis of indigo. Many microorganisms involved in the biosynthesis of indigo have been isolated and characterized, and monooxygenase and dioxygenase have been identified to catalyze indigo biosynthesis. Some genes encoding for these enzymes have been cloned and used to construct "engineering bacteria". With this kind of bacteria, more efficient fermentation systems for indigo production have been exploited. In the meantime, biotransformation of the indigo produced by microorganisms has been under investigation. These progresses will bring us a greener method of indigo and indigo-like pigments production.
Biotechnology ; Coloring Agents ; metabolism ; Dioxygenases ; metabolism ; Fermentation ; Indigo Carmine ; Indoles ; metabolism ; Mixed Function Oxygenases ; metabolism ; Pseudomonas ; metabolism ; Sphingomonas ; metabolism

Accessed to literatures at home and abroad, we introduced the process of indigo naturalis transforming from dyestuff industry into pharmaceutical industry. It is affirmed that the precursors of indigo and indirubin are isatan A, isatan B, isatan C and indicant. Meanwhile, author clarified the mechanism of transformation for these precursors transforming into indigo and indirubin. And we summarized methods of determination for these precursors. In summary, these references provide us accordance of study on processing principle of Indigo naturalis, and lay the foundation for technics of making indigo and indirubin entering into modern industry.
Indigo Carmine ; Indoles ; chemistry ; metabolism ; Oxidation-Reduction ; Pigmentation ; Plants ; metabolism ; Temperature

Different harvest times of Isatidis Folium had a significant effect on the yield and the quality of Isatidis Radix and Isatidis Folium. The harvest could increase the yield of Isatidis Folium, but reduce the yield of Isatidis Radix, the quality of Isatidis Radix and Isatidis Folium. One, two and three harvests of the Isatidis Folium reduced the yield of Isatidis Radix as 18.3%, 58.6%, 67.4% and increased the yield of the Folium as 107.3%, 86.3% and 116.6%. Ethanol-soluble extract of Isatidis Radix was 42.50%, 42.24%, 31.77%, which were 1.19%, 1.79%, 26.13% lower than those of the control, respectively. The water-soluble extract, indirubin, indigo content reduced with increase of the harvest times. Indirubin contents with two or three times harvests were higher than that of the control, but the content of water-soluble extract, ethanol-soluble extract, indigo were lower than those of the control.
Agriculture ; methods ; Desert Climate ; Drugs, Chinese Herbal ; chemistry ; metabolism ; Indigo Carmine ; Indoles ; metabolism ; Isatis ; metabolism ; Plant Leaves ; chemistry ; metabolism ; Plant Roots ; chemistry ; metabolism ; Quality Control ; Time Factors

The phenylacetone monooxygenase, isolated from Thermobifida fusca, mainly catalyzes Baeyer-Villiger oxidation reaction towards aromatic compounds. Met446 plays a vital role in catalytic promiscuity, based on the structure and function of phenylacetone monooxygenase. Mutation in Met446 locus can offer enzyme new catalytic feature to activate C-H bond, oxidizing indole to finally generate indigo and indirubin, but the yield was only 1.89 mg/L. In order to further improve the biosynthesis efficiency of the whole-cell catalyst, metabolic engineering was applied to change glucose metabolism pathway of Escherichia coli. Blocking glucose isomerase gene pgi led to pentose phosphate pathway instead of the glycolytic pathway to become the major metabolic pathways of glucose, which provided more cofactor NADPH needed in enzymatic oxidation of indole. Engineering the host E. coli led to synthesis of indigo and indirubin efficiency further increased to 25 mg/L. Combination of protein and metabolic engineering to design efficient whole-cell catalysts not only improves the synthesis of indigo and indirubin, but also provides a novel strategy for whole-cell catalyst development.
Escherichia coli ; genetics ; metabolism ; Glucose ; metabolism ; Indigo Carmine ; metabolism ; Indoles ; metabolism ; Industrial Microbiology ; methods ; Metabolic Engineering ; Metabolic Networks and Pathways ; Protein Engineering

BACKGROUNDQacA, a main exporter mediating the multidrug-resistance of Staphylococcus aureus to a variety of antiseptics and disinfectants, possesses a topology of 14 alpha-helical transmembrane segments (TMS). Our study aimed to determine the importance and topology of amino acid residues in and flanking the cytoplasmic end of TMS5.

METHODSSite-directed mutagenesis was used to mutate 5 residues, including L146, A147, V148, W149 and S150, into cysteine. A minimum inhibitory concentration (MIC) and transport assay with or without N-ethylmaleimide (NEM) were performed to analyse the function of these mutants.

RESULTSAll of the mutants showed comparable protein expression levels. MIC analysis suggested that mutant W149C showed low resistance levels to the drugs, but the mutations at L146, A147, V148, and S150C had little or no effect on the resistance level. And the results of the fluorimetric transport assay were in agreement with those of MIC analysis, that is to say, W149C did not allow transport to the substrates to be tested, while the other mutants retained significant transport ability. The reaction of the different mutant proteins with Fluorescein-NEM revealed that the mutant L146C was highly reactive with NEM; the W149C and S150C mutants were moderately reactive; A147C was barely reactive and V148C showed no reactivity.

CONCLUSIONSThe study identified that residues W149 and S150 situated at the interface of the aqueous: lipid junction as functionally important residues, probably involved in the substrate binding and translocation of QacA.

Bacterial Proteins ; chemistry ; physiology ; Drug Resistance, Bacterial ; Ethylmaleimide ; pharmacology ; Indoles ; metabolism ; Membrane Transport Proteins ; chemistry ; physiology ; Structure-Activity Relationship

This study is to investigate the effect of fascaplysin on human cervical cancer cells (HeLa) in order to provide insights into the mechanisms of growth suppression involved in fascaplysin-mediated apoptosis. Cytotoxic activity of fascaplysin on HeLa cells was determined using MTT assay, cell cycle analysis, and apoptosis (Annexin V-FITC and PI double staining) studies. The role of the molecules in cell cycle regulation and apoptosis was analyzed by Western blotting and flow cytometry. Fascaplysin markedly inhibited HeLa cells proliferation in a dose-dependent manner, however, did not provoke G1 phase arrest in HeLa cells with downregulation of CDK4, cyclin D1 and CDK4-specific Ser795 pRb phosphorylation. Furthermore, fascaplysin induced significantly apoptosis evidenced by sub-G1 peak and Annexin V-FITC and PI double staining. The molecular mechanism of fascaplysin-induced apoptosis was characterized with the activation of caspase-3, -8, and -9, truncation of Bid, release of cytochrome c into cytosol, and down-regulation of Bcl-2 level. Fascaplysin exhibits anti-proliferation effect towards human cervical cancer HeLa cells through induction of apoptosis via extrinsic death pathway and mitochondrial pathway, but not arresting cell cycle progression at G1 phase. All together, these data sustain our contention that fascaplysin has anticancer properties and merits further investigation as a potential therapeutic agent.
Apoptosis ; drug effects ; Cell Cycle Checkpoints ; drug effects ; Cell Proliferation ; drug effects ; HeLa Cells ; Humans ; Indoles ; pharmacology ; Mitochondria ; metabolism

OBJECTIVETo investigate the effect of NSC348884, a nucleophosmin small molecular inhibitor, on the growth of hepatocellular carcinoma cell line HepG2 and its underlying mechanism.

METHODSAfter HepG2 cells were treated by NSC348884 for 4 days, the effect of HepG2 cells on proliferation was measured by methyl thiazolyl tetrazolium (MTT) assay, the expression variation of nucleophosmin oligomer and monomer was measured using Western blotting, and cell apoptotic rate was detected by flow cytometry.

RESULTSThe proliferation of HepG2 cells was remarkably inhibited by NSC348884 treatment when the drug concentration ranged from 1 micromol/L to 10 micromol/L (P < 0.05), with a 50% inhibiting concentration of 1.4 micromol/L. After treatment for 24 hours, the expression level of nucleophosmin oligomer decreased obviously while that of nucleophosmin monomer increased (both P < 0.05). After treatment by 1 micromol/L and 2 micromol/L NSC348884, the 24-hour apoptotic rates of HepG2 cells were (13.770 +/- 0.335)% and (19.021 +/- 0.237)%, respectively, which were significantly higher than in the control group (6.950 +/- 0.207)% (P < 0. 05).

CONCLUSIONNSC348884 can promote the transformation of nucleophosmin oligomer to monomer and thus inhibit the growth of hepatic carcinoma cell line HepG2 in vitro.

Apoptosis ; drug effects ; Cell Proliferation ; drug effects ; Hep G2 Cells ; Humans ; Indoles ; pharmacology ; Nuclear Proteins ; antagonists & inhibitors ; metabolism

To investigate the effect of a microsomal prostaglandin E synthase-1 (mPGES-1) inhibitor MK886 on cell cycle of the human acute myeloid leukemia HL-60 cells. HL-60 cells were treated with different concentration of MK886 (10, 25, 50 µmol/L) for 24 h. Flow cytometry, Western blot and ELISA were used to measure cell cycle, cyclin D1, mPGES-1, PGE(2), Akt, P-Akt and C-MYC. The results indicated that after treated with MK886, the percentage of HL-60 cells decreased in G(0)/G(1) phase and increased in S phase, and expressions of mPGES-1, cyclin D1, P-Akt and C-MYC and synthesis of PGE(2) decreased significantly. It is concluded that MK886 can arrest HL-60 cells in G(0)/G(1) phase, the mechanism of which is possibly associated to inhibition of mPGES-1 expression, reduction of PGE(2) synthesis, suppression of Akt phosphorylation and C-MYC expression, down-regulation of cyclin D1 expression.
Cell Cycle ; drug effects ; HL-60 Cells ; Humans ; Indoles ; pharmacology ; Intramolecular Oxidoreductases ; antagonists & inhibitors ; Leukemia ; metabolism ; pathology ; Prostaglandin-E Synthases

OBJECTIVETo investigate the role of protein kinase C (PKC) in thrombin-induced monocyte chemoattractant protein-1(MCP-1) release by human lung fibroblasts (HLF-1).

METHODSCultured human lung fibroblasts HLF-1 were incubated with different concentrations of PKC inhibitors before by thrombin stimulation. MCP-l protein levels in the supernatants were assessed using ELISA, and MCP-1 mRNA levels in the cell lysate were measured by quantitative real-time PCR.

RESULTSThe broad spectrum PKC inhibitors bisindolylmaleimide I and RO-31-8220 obviously inhibited thrombin-induced MCP-l mRNA and protein expressions in HLF-1 cells, whereas Ca(2+)-dependent PKC inhibitor Go 6976 had no such effects.

CONCLUSIONCa(2+)-independent PKC mediates thrombin-induced MCP-1 release in cultured HLF-1 cells.

Cell Line ; Cells, Cultured ; Chemokine CCL2 ; metabolism ; Fibroblasts ; metabolism ; Humans ; Indoles ; pharmacology ; Lung ; cytology ; metabolism ; Protein Kinase C ; antagonists & inhibitors ; Thrombin ; pharmacology