Aims: Lytic polysaccharide monooxygenase (LPMO) is an enzyme capable of cleaving glycoside bonds of recalcitrant polysaccharides through an oxidative mechanism. LPMO activity, in synergy with hydrolytic enzymes, increases the production of monomer sugars from the biodegradation of lignocellulose. This study was aimed at evaluating actinomycete S2 strain LPMO activity based on the release of xylose as one of reducing sugar and hydrogen peroxide (H2O2) in the course of lignocellulosic biodegradation. Methodology and results: The oxidation activity of LPMO from actinomycete S2 strain was measured by using the substrate of Avicel supplemented with ascorbic acid and copper ions (Cu2+) to identify its effect on the release of xylose as one of reducing sugar. The optimum incubation time for the LPMO production was also conducted. Further, H2O2 quantitative analysis was performed as by-product of LPMO activity and 16S rRNA gene sequence of actinomycete S2 strain were subsequently determined. We found that supplementation of 1 mM ascorbic acid and 0.2 mM Cu2+ increased xylose as one of reducing sugar production by up to 5-fold from 255.03 to 1290 μg/mL after an optimal incubation period of 6 days. Based on H2O2 production, the LPMO activity of actinomycete S2 strain was 0.019 ± 0.001 U/mL. There is likelihood that LPMO activity derived from actinomycete S2 strain has a synergistic effect with the activity of other lignocellulose-degrading enzymes. This actinomycete showed 99% similarity to the 16S rRNA gene sequence of Streptomyces avermitilis strain EAAG80. Conclusion, significance, and impact of study LPMO enzyme activity from actinomycete S2 strain as determined by the production of reducing sugar and H2O2 was greatly increased by supplementation with ascorbic acid as an electron donor and Cu2+ ions. To the best of our knowledge, this is the first elucidation of LPMO activity from an indigenous Indonesian actinomycete.
Mixed Function Oxygenases--metabolism ; Lignin--metabolism

The 4-hydroxyphenylacetate 3-hydroxylase (4HPA3H), originated from Escherichia coli, converts p-coumaric acid to caffeic acid. In order to improve the efficiency of caffeic acid biosynthesis, we engineered E. coli for overexpression of 4HPA3H. The high-density fermentation of the engineered E. coli was conducted in a 5 L bioreactor. Subsequently, the conditions for whole-cell biocatalysis were optimized. The dry cell weight of the 4HPA3H-expressed strain reached 34.80 g/L. After incubated in the bioreactor for 6 h, 18.74 g/L (0.85 g/(L·OD₆₀₀)) of caffeic acid was obtained, with a conversion rate of 78.81% achieved. To the best of our knowledge, the titer of caffeic acid is the highest reported to date. The high-density fermentation of E. coli for overexpression of 4HPA3H and the efficient biosynthesis of caffeic acid may facilitate future large-scale production of caffeic acid.
Caffeic Acids ; Escherichia coli/metabolism* ; Fermentation ; Metabolic Engineering ; Mixed Function Oxygenases/metabolism* ; Phenylacetates

17α hydroxylase is a key enzyme for the conversion of progesterone to prepare various progestational drug intermediates. To improve the specific hydroxylation capability of this enzyme in steroid biocatalysis, the CYP260A1 derived from cellulose-mucilaginous bacteria Sorangium cellulosum Soce56 and the Fpr and bovine adrenal-derived Adx_4-108 derived from Escherichia coli str. K-12 were used to construct a new electron transfer system for the conversion of progesterone. Selective mutation of CYP260A1 resulted in a mutant S276I with significantly enhanced 17α hydroxylase activity, and the yield of 17α-OH progesterone reached 58% after optimization of the catalytic system in vitro. In addition, the effect of phosphorylation of the ferredoxin Adx_4-108 on 17α hydroxyl activity was evaluated using a targeted mutation technique, and the results showed that the mutation Adx_4-108T69E transferred electrons to S276I more efficiently, which further enhanced the catalytic specificity in the C17 position of progesterone, and the yield of 17α-OH progesterone was eventually increased to 74%. This study provides a new option for the production of 17α-OH progesterone by specific transformation of bacterial-derived 17α hydroxylase, and lays a theoretical foundation for the industrial production of progesterone analogs using biotransformation method.
Animals ; Cattle ; Progesterone/metabolism* ; Hydroxylation ; Biocatalysis ; Electron Transport ; Mixed Function Oxygenases/metabolism*

Taxol is a secondary metabolite with prominent anti-tumor activity, but the yield cannot meet the growing clinical demand due to lower content in yew. Now, most enzyme genes involved in taxol biosynthesis have been cloned and identified, so that obtaining this drug by using synthetic biology method has become a hotspot in recent years. However, most hydroxylases involved in taxol biosynthetic pathway have not been explored. Here, we reviewed the progress on the biosynthesis pathway of taxol, especially concerning hydroxylase. The future research areas of taxol biosynthesis through synthetic biology were also discussed to provide basis for the discovery of uncharacterized hydroxylase genes and the mass taxol production by synthetic biology technology.
Biosynthetic Pathways ; Mixed Function Oxygenases ; metabolism ; Paclitaxel ; biosynthesis ; Synthetic Biology ; Taxus ; enzymology

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

OBJECTIVEAberrant expression of ten-eleven translocation 1 (TET1) plays a critical role in tumor development and progression. We systematically summarized the latest research progress on the role and mechanisms of TET1 in cancer biology.

DATA SOURCESRelevant articles published in English from 1980 to April 2016 were selected from the PubMed database. The terms "ten-eleven translocation 1," "5mC," "5hmC," "microRNA," "hypoxia," and "embryonic stem cell" were used for the search.

STUDY SELECTIONArticles focusing on the role and mechanism of TET1 in tumor were reviewed, including clinical and basic research articles.

RESULTSTET proteins, the key enzymes converting 5-methylcytosine to 5-hydroxymethylcytosine, play vital roles in DNA demethylation regulation. Recent studies have shown that loss of TET1 is associated with tumorigenesis and can be used as a potential biomarker for cancer therapy, which indicates that TET1 serves as tumor suppressor gene. Moreover, besides its dioxygenase activity, TET1 could induce epithelial-mesenchymal transition and act as a coactivator to regulate gene transcription, such as developmental regulator in embryonic stem cells (ESCs) and hypoxia-responsive gene in cancer. The regulation of TET1 is also correlated with microRNA in a posttranscriptional modification process. Hence, it is complex but critical to comprehend the mechanisms of TET1 in the biology of ESCs and cancer.

CONCLUSIONSTET1 not only serves as a demethylation enzyme but also plays multiple roles during tumorigenesis and progression. More studies should be carried out to elucidate the exact mechanisms of TET1 and its associations with cancer before considering it as a therapeutic tool.

Animals ; Biomarkers ; metabolism ; Carcinogenesis ; genetics ; metabolism ; pathology ; Humans ; MicroRNAs ; genetics ; Mixed Function Oxygenases ; genetics ; metabolism ; Proto-Oncogene Proteins ; genetics ; metabolism

Interests on the effects of cytochrome P450 (CYP450) monooxygenases and epoxyeicosatrienoic acids (EETs) on myocardial ischemic-reperfusion injury has been increased in recent years. The CYP450/EET system may influence the degree of myocardial ischemic-reperfusion injury through "poly-targets", such us oxygen free radical, calcium overload, leukocytes adherence, nitric oxide, ATP-sensitive K+ channels, and mitogen activated protein kinase. The exaggeration or recovery of injury depends on the physical status. Study of factors that affects CYP450/EET, particularly identification of their involvement in cardioprotective signaling and specific roles, will elucidate the mechanisms of myocardial ischemic-reperfusion injury, and find a new way of prevention and treatment. This article will review the relationship between the changes of CYP450/EETs system and myocardial ischemic-reper-
Animals ; Cytochrome P-450 Enzyme System ; metabolism ; Eicosapentaenoic Acid ; metabolism ; Humans ; Mixed Function Oxygenases ; metabolism ; Myocardial Reperfusion Injury ; etiology ; metabolism

Geldanamycin (Gdm), an inhibitor of heat shock protein 90 (Hsp90), shows antitumor and antivirus bioactivity. Most Geldanamycin biosynthetic genes have been cloned from the genome library of Streptomyces hygroscopicus 17997. In this report, polyketide synthase (pks) gene, mono-oxygenase (gdmM) gene and carbamoyltransferase gene (gdmN) were subjected to inactivation. Three gene disrupted mutants (deltapks, deltagdmM and deltagdmN) were obtained by double crossover. No Geldanamycin production was detected in three mutant strains cultured in fermentation broth. Gene complementation experiments excluded the possible polar effect of gene disruption on other genes. These results confirmed that pks, gdmM and gdmN genes were essential for Geldanamycin biosynthesis.
Benzoquinones ; metabolism ; Carboxyl and Carbamoyl Transferases ; genetics ; Lactams, Macrocyclic ; metabolism ; Mixed Function Oxygenases ; genetics ; Polyketide Synthases ; genetics ; Streptomyces ; genetics ; metabolism

Hyoscyamine and scopolamine are two main alkaloids in Atropa belladonna with great medicinal value. In this paper, the contents of hyoscyamine and scopolamine, the upstream products in alkaloid synthesis, and the expression levels of key enzyme genes PMT, TRⅠ and H6H in secondary metabolism of A. belladonna seedlings were measured to clarify the mechanism of nitrogen forms regulating alkaloids synthesis.The results showed that the 50/50 (NH⁺₄/NO⁻₃) treatment was more favorable for the accumulation of alkaloids and the conversion of hyoscyamine to scopolamine. The content of putrescine was almost consistent with the change of key enzymes activities in the synthesis of putrescine, they both increased with the rise of ammonium ratio, reaching the highest at 75/25 (NH⁺₄/NO⁻₃). The detection of signaling molecule nitric oxide (NO) showed that the NO concentration decreased with the decrease of nitrate proportion. Further detection of gene expression levels of PMT, TRⅠ and H6H in TAs synthesis pathway showed that a certain amount of ammonium promoted the expression of PMT and H6H in roots. When the ratio of ammonium to nitrate was 50/50, PMT, TRⅠ and H6H in leaves and roots had higher expression levels. It can be speculated that the regulation of the formation of hyoscyamine to scopolamine by nitrogen forms mainly through affecting the expression of key enzyme genes. 50/50 (NH⁺₄/NO⁻₃) treatment increased the gene expression of TRⅠ in both leaves and roots as well as PMT and H6H in roots, promoting the synthesis of putrescine to hyoscyamine and the conversion of hyoscyamine to scopolamine.
Atropa belladonna ; enzymology ; genetics ; Gene Expression Regulation, Plant ; Hyoscyamine ; biosynthesis ; Mixed Function Oxygenases ; Nitrogen ; metabolism ; Scopolamine ; metabolism

OBJECTIVE: To determine the difference in aspartyl-(asparaginyl) beta-hydroxylase (AAH) expression level in villi between patients with missed abortion and normal women with early pregnancy, and to confirm the expression loci of AAH in villi. METHODS: A total of 50 patients of missed abortion were collected and categorized into a test group, which was subdivided into Group 1 and Group 2. Patients in Group 1 (n=20) were of confirmed etiological disorders while those in Group 2 (n=30) showed no obviously etiological clues. In addition, 20 women of early pregnancy with artificial abortion were categorized into a control group, whose embryos were sonographically confirmed alive before surgery. The 50 patients of missed abortion were also subdivided into a group within 4 weeks and a group over 4 weeks according to the time that the embryo stayed in utrine after death. Immunohistochemical technique and computer image analysis were used to detect the expression loci and the level of AAH in villi. RESULTS: AAH was expressed in the endochylema and nucleus of trephocyte both in missed abortion and normal early pregnancy. The expression level of AAH in villi of missed abortion was much lower than that of in villi of normal early pregnancy (P<0.05). The expression level had no difference between different groups of patients with missed abortion(P>0.05). CONCLUSION Low expression of AAH in the endochylema and nucleus of trephocyte may play a role in patients with missed abortion.
Abortion, Missed ; enzymology ; Adult ; Case-Control Studies ; Chorionic Villi ; enzymology ; Female ; Humans ; Mixed Function Oxygenases ; genetics ; metabolism ; Pregnancy