166 research outputs found
Oxidoreductase reactions for cosmeceutical production from soy bean products
One of the recent trends in cosmetics industry is using natural and organic ingredients in the manufacturing of cosmetics. Although various plant extracts are major sources of these ingredients, they usually contain complex mixtures with few functionally bioactive ingredients, so that clear scientific proof and supporting data on their effects and efficacy of the ingredients on our body and skin are lacking. Whereas specific biotransformation reactions of single compound can provide various biologically active compounds for their functional studies. Among such biotransformations, we have special interests in producing bioactive natural products(isoflavonoids) derived from soybean such as daidzein and genistein using various oxidoreductases such as P450, tyrosinase, isoflavone reductase and glycoside oxidase, which can control hydroxylation, oxidation/reduction and deglycosylation.
In this talk I will present several examples of producing modified isoflavonoids using such enzymes or enzyme systems, which can be used as cosmeceuticals.
Since most of such oxidoreductase systems require electron transfer system, using recombinant E.coli system, construction of an efficient enzyme systems and protein engineering for their specific activity improvement, cofactor NAD(P)H optimization and related metabolic engineering, enhancing transport of substrate and product, etc. will be applied and discussed using isoflavonoids as model systems. In addition, we would like to explain how “systems and synthetic biological approaches” work for these enzyme reactions, and what kinds of strategies are desirable to develop their industrial scale biotransformations
Characterization of GDP-mannose Pyrophosphorylase from Escherichia Coli O157:H7 EDL933 and Its Broad Substrate Specificity
GDP-mannose pyrophosphorylase gene (ManC) of Escherichia coli (E. coli) O157 was cloned and expressed as a highly soluble protein in E. coli BL21 (DE3). The enzyme was subsequently purified using hydrophobic and ion exchange chromatographies. ManC showed very broad substrate specificities for four nucleotides and various hexose-1-phosphates, yielding ADP-mannose, CDP-mannose, UDP-mannose, GDP-mannose, GDP-glucose and GDP-2-deoxy-glucose
The dynamic transcriptional and translational landscape of the model antibiotic producer Streptomyces coelicolor A3(2)
Individual Streptomyces species have the genetic potential to produce a diverse array of natural products of commercial, medical and veterinary interest. However, these products are often not detectable under laboratory culture conditions. To harness their full biosynthetic potential, it is important to develop a detailed understanding of the regulatory networks that orchestrate their metabolism. Here we integrate nucleotide resolution genome-scale measurements of the transcriptome and translatome of Streptomyces coelicolor, the model antibiotic-producing actinomycete. Our systematic study determines 3,570 transcription start sites and identifies 230 small RNAs and a considerable proportion (∼21%) of leaderless mRNAs; this enables deduction of genome-wide promoter architecture. Ribosome profiling reveals that the translation efficiency of secondary metabolic genes is negatively correlated with transcription and that several key antibiotic regulatory genes are translationally induced at transition growth phase. These findings might facilitate the design of new approaches to antibiotic discovery and development
In silico identification of metabolic engineering strategies for improved lipid production in Yarrowia lipolytica by genome-scale metabolic modeling
Background
Yarrowia lipolytica, an oleaginous yeast, is a promising platform strain for production of biofuels and oleochemicals as it can accumulate a high level of lipids in response to nitrogen limitation. Accordingly, many metabolic engineering efforts have been made to develop engineered strains of Y. lipolytica with higher lipid yields. Genome-scale model of metabolism (GEM) is a powerful tool for identifying novel genetic designs for metabolic engineering. Several GEMs for Y. lipolytica have recently been developed; however, not many applications of the GEMs have been reported for actual metabolic engineering of Y. lipolytica. The major obstacle impeding the application of Y. lipolytica GEMs is the lack of proper methods for predicting phenotypes of the cells in the nitrogen-limited condition, or more specifically in the stationary phase of a batch culture.
Results
In this study, we showed that environmental version of minimization of metabolic adjustment (eMOMA) can be used for predicting metabolic flux distribution of Y. lipolytica under the nitrogen-limited condition and identifying metabolic engineering strategies to improve lipid production in Y. lipolytica. Several well-characterized overexpression targets, such as diglyceride acyltransferase, acetyl-CoA carboxylase, and stearoyl-CoA desaturase, were successfully rediscovered by our eMOMA-based design method, showing the relevance of prediction results. Interestingly, the eMOMA-based design method also suggested non-intuitive knockout targets, and we experimentally validated the prediction with a mutant lacking YALI0F30745g, one of the predicted targets involved in one-carbon/methionine metabolism. The mutant accumulated 45% more lipids compared to the wild-type.
Conclusion
This study demonstrated that eMOMA is a powerful computational method for understanding and engineering the metabolism of Y. lipolytica and potentially other oleaginous microorganisms.This research was supported by the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (NRF2017R1E1A1A01073523) and Industrial Strategic technology development program, 20002734 funded by the Ministry of Trade, Industry & Energy (MI,
Korea
Preparative Synthesis of dTDP-L-Rhamnose Through Combined Enzymatic Pathways
dTDP-L-rhamnose, an important precursor of O-antigen, was prepared on a large scale from dTMP by executing an one-pot reaction in which six enzymes are involved. Two enzymes, dTDP-4-keto-6-deoxy-D-glucose 3,5-epimerase and dTDP-4-keto-rhamnose reductase, responsible for the conversion of dTDP-4-keto-6-deoxy- D-glucose to dTDP-L-rhamnose, were isolated from their putative sequences in the genome of Mesorhizobium loti, functionally expressed in Escherichia coli, and their enzymatic activities were identified. The two enzymes were combined with an enzymatic process for dTDP-4- keto-6-deoxy-D-glucose involving TMP kinase, acetate kinase, dTDP-glucose synthase, and dTDP-glucose 4,6- dehydratase, which allowed us to achieve a preparative scale synthesis of dTDP-L-rhamnose using dTMP and glucose-1-phosphate as starting materials. About 82% yield of dTDP-L-rhamnose was obtained based on initial dTMP concentration at 20 mM dTMP, 1 mM ATP, 10 mM NADH, 60 mM acetyl phosphate, and 80 mM glucose-1- phosphate. From the reaction with 20 ml volume, approximately 180 mg of dTDP-L-rhamnose was obtained in an overall yield of 60% after two-step purification, that is, anion exchange chromatography and gel filtration for desalting. The purified product was identifiedbyHPLC, ESI-MS,andNMR,showingabout95%purity
One-pot Enzymatic Synthesis of Deoxy-thymidine-diphosphate (TDP)-2-deoxy-∝-d-glucose Using Phosphomannomutase
Production of deoxy-thymidine-diphosphate (TDP)-sugars as substrates of glycosyltransferases, has been one of main hurdles for combinatorial antibiotic biosynthesis, which combines sugar moiety with aglycon of various antibiotics. Here, we report the one-pot enzymatic synthesis of TDP-2-deoxy-glucose employing high efficient TMP kinase (TMK; E.C. 2.7.2.12), acetate kinase (ACK; E.C. 2.7.1.21), and TDP-glucose synthase (TGS; E.C. 2.7.7.24) with phosphomannomutase (PMM; E.C. 5.4.2.8). In this study, replacing phosphoglucomutase (PGM; E.C. 5.4.2) by PMM from Escherichia coli gave four times higher specific activity on 2-deoxy-6-phosphate glucose, suggesting that the activity on 2-deoxy-glucose-6-phosphate was mainly affected by PMM activity, not PGM activity. Using an in vitro system starting from TMP and 2-deoxy-glucose-6-phosphate glucose, TDP-2-deoxy-glucose (63% yield) was successfully synthesized. Considering low productivity of NDP-sugars from cheap starting materials, this paper showed how production of NDP-sugars could be enhanced by controlling mutase activity
Dilated Cardiomyopathy in a 2 Month-Old Infant: A Severe Form of Hypocalcemia With Vitamin D Deficient Rickets
Dilated cardiomyopathy, which mostly has an idiopathic etiology or is caused by genetic inheritance or infection, can cause irreversible congestive heart failure. Hypocalcemia is a rare etiology of reversible dilated cardiomyopathy. Here we report the case of a two-month-old girl with congestive heart failure who was diagnosed as having dilated cardiomyopathy secondary to hypocalcemia. After calcium and vitamin D replacement therapy, the patient showed a rapid reduction in hypocalcemic tetany and a rapid recovery of left ventricular function. The cause of the hypocalcemia was vitamin D deficient rickets. She was exclusively breast-fed as an infant, and her mother had a vitamin D deficiency and was diagnosed with osteomalacia
Chuna (or Tuina) Manual Therapy for Musculoskeletal Disorders: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Objective. To review the literature and systematically evaluate the effectiveness of Chuna (or Tuina) manual therapy (C[T]MT) on pain and function for musculoskeletal disorders. Methods. We searched 15 English, Chinese, Japanese, and Korean databases using relevant keywords. All randomized controlled trials (RCTs) of C(T)MT for musculoskeletal disorders were considered, and we limited analyses to studies with a low-risk bias for randomization and/or allocation concealment. Results. Sixty-six RCTs with 6,170 participants were included. One sham-controlled RCT showed that C(T)MT relieved pain more effectively than a sham control (SMD -3.09 [-3.59, -2.59]). For active-controlled RCTs, pooled meta-analysis showed that C(T)MT had statistically significant effects on pain reduction, especially compared to traction (P<0.00001), drugs (P=0.04), and physical therapies (P<0.0001). For functional improvement, combined effects of C(T)MT with drugs (P=0.04) and traction (P=0.05) also showed similar positive effects. Conclusions. This systematic review suggests that C(T)MT is safe and effective for pain reduction and functional improvement for musculoskeletal diseases; however, the evidence for functional improvement was not as strong as for pain reduction. For future studies, high-quality RCTs such as sham-controlled studies with standardized interventions are needed to provide sufficient evidence on the effects of C(T)MT for musculoskeletal diseases. Protocol registration number is CRD42016038307 04/07/2016
Development of a CHO cell line for stable production of recombinant antibodies against human MMP9
Abstract
Background
Human matrix metalloproteinase 9 (hMMP9) is a biomarker in several diseases, including cancer, and the need for developing detectors and inhibitors of hMMP9 is increasing. As an antibody against hMMP9 can be selectively bound to hMMP9, the use of anti-MMP9 antibody presents new possibilities to address hMMP9-related diseases. In this study, we aimed to establish a stable Chinese hamster ovary (CHO) cell line for the stable production of antibodies against hMMP9.
Results
Weconstructed recombinant anti-hMMP9 antibody fragment-expressing genes and transfected these to CHO cells. We chose a single clone, and successfully produced a full-sized antibody against hMMP9 with high purity, sensitivity, and reproducibility. Subsequently, we confirmed the antigen-binding efficiency of the antibody.
Conclusions
We developed a novel recombinant anti-hMMP9 antibody via a CHO cell-based mammalian expression system, which has a high potential to be used in a broad range of medical and industrial areas
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