[Preparation and characterization of chicken anti-human B7-H4 IgY polyclonal antibody].

Objective To prepare anti-human B7 homolog 4 (B7-H4) egg yolk immunoglobulins (IgY) polyclonal antibody and establish a double-antibody sandwich ELISA for the detection of soluble B7-H4 (sB7-H4) protein in human serum. Methods Bioinformatics was used to screen specific B cell epitope peptides of human sB7-H4. New Hyland Grey laying hens were immunized with these peptides, and the eggs from the immunized hens were collected to purify chicken anti-human B7-H4 IgY antibody. The purity, concentration and titer of the antibody were detected, and its specificity and function of the antibodies were verified by using ELISA, Western blot analysis and flow cytometry, respectively. A double-antibody sandwich ELISA was established to detect sB7-H4 in clinical samples by using the IgY antibody. Comparative detection was performed using a commercialized ELISA kit on the same set of clinical samples. Results The chicken anti-human B7-H4 IgY antibodies were successfully prepared and proven to be highly specific for the human B7-H4 protein. The ELISA established with the IgY polyclonal antibody detected significantly higher levels of soluble B7-H4 in the serum of patients with ovarian cancer and benign ovarian tumors compared to healthy controls. These results were consistent with the detection results obtained using a commercialized ELISA kit. However, the ELISA with IgY antibody exhibited higher sensitivity than the commercialized kit. Conclusion The chicken polyclonal antibody against human B7-H4 IgY is successfully prepared, and a double-antibody sandwich ELISA suitable for detecting sB7-H4 protein in human serum is established.

Biosynthesis of the Plant Coumarin Osthole by Engineered Saccharomyces cerevisiae.

Osthole is a coumarin compound found in the traditional Chinese medicine Cnidium monnieri. Extensive studies have shown that osthole exhibits many medicinal properties, and recently, researchers have found that it possesses potent airway-relaxation activity by inhibiting phosphodiesterase 4D activity, making it a potential novel bronchodilator that does not target ß2-adrenoceptors for asthma treatment. Here, we report the complete biosynthesis of osthole in engineered yeast. We created an umbelliferone (UMB)-producing strain by reconstituting the complete UMB pathway in yeast. We found that coumarin synthase (COSY) is essential for the conversion of 2',4'-dihydroxycinnamoyl-CoA into UMB in yeast; this conversion has been treated as a spontaneous step in previously reported UMB-producing microbials. By introducing downstream prenyltransferase and methyltransferase genes and addressing problems such as protein expression and cofactor supply to fulfill the downstream steps, complete biosynthesis of osthole was achieved. Finally, through metabolic engineering, to ensure precursor supply, and the debugging of rate-limited steps, the osthole titer reached 108.10 mg/L in shake flasks and 255.1 mg/L in fed-batch fermentation. Our study is the first to produce osthole using engineered microbes, providing a blueprint for the supply of plant-derived osthole via microbial fermentation, which will remove the barriers of resource limitations for osthole-based drug development.

Research Progress of Green Solvent in CsPbBr3 Perovskite Solar Cells.

In optoelectronic applications, all-Brominated inorganic perovskite CsPbBr3 solar cells have received a great deal of attention because of their remarkable stability and simplicity of production. Most of the solvents used in CsPbBr3 perovskite solar cells are toxic, which primarily hinders the commercialization of the products. In this review, we introduce the crystal structure and fundamental properties of CsPbBr3 materials and the device structure of perovskite cells, summarize the research progress of green solvents for CsPbBr3 PSCs in recent years from mono-green solvent systems to all-green solvent systems, and discuss the approaches to improving the PCE of CsPbBr3 PSCs, intending to facilitate the sustainable development of CsPbBr3 perovskite solar cells. Finally, we survey the future of green solvents in the area of CsPbBr3 perovskite solar cells.

Identification of a novel multifunctional oxidosqualene cyclase from Zea mays sheds light on the biosynthetic pathway of three pentacyclic triterpenoids.

Zea mays (maize) is an important agricultural crop that produces a variety of valuable terpenoids, including several triterpenoids. However, no oxidosqualene cyclase (OSC) enzymes, which catalyze the first step in triterpenoid biosynthesis, have been identified in maize. Here, we identified a novel OSC (ZmOSC1) in maize using a combination of genomic mining and phylogenetic analyses. To functionally characterize the candidate OSC, we constructed a yeast strain that produced high levels of 2,3-oxidosqualene. When ZmOSC1 was expressed in this strain, three compounds were detected and identified as hop-17(21)-en-3-ol, hopenol B and simiarenol, respectively. For their biosynthesis, we proposed a potential cyclization mechanism catalyzed by ZmOSC1 via the generation of a dammarenyl cation, followed by sequential cationic ring expansion, cyclization, cationic migration and further proton elimination. This study discovered and characterized an OSC from maize for the first time, and laid a foundation to produce three bioactive pentacyclic triterpenes, hop-17(21)-en-3-ol, hopenol B and simiarenol, using synthetic biology approaches.

High-level sustainable production of the characteristic protopanaxatriol-type saponins from Panax species in engineered Saccharomyces cerevisiae.

The Chinese medicinal plant Panax notoginseng has been traditionally used to activate blood flow and circulation, and to prevent blood stasis. P. notoginseng contains protopanaxatriol (PPT)-type saponins as its main active compounds, thus distinguishing it from the other two famous Panax species, P. ginseng and P. quinquefolius. Ginsenoside Rg1 (Rg1), notoginsenoside R1 (NgR1), and notoginsenoside R2 (NgR2) are three major PPT-type saponins in P. notoginseng and possess potential cardiovascular protection activities. However, their use in medical applications has long been hampered by the lack of sustainable and low-cost industrial-scale preparation methods. In this study, a PPT-producing yeast chassis strain was designed and constructed based on a previously constructed and optimized protopanaxadiol (PPD)-producing Saccharomyces cerevisiae strain, and further optimized by systemically engineering and optimizing the expression level of its key P450 biopart. Rg1-producing yeast strains were constructed by introducing PgUGT71A53 and PgUGT71A54 into the PPT chassis strain. The fermentation titer of Rg1 reached 1.95 g/L. A group of UDP-glycosyltransferases (UGT) from P. notoginseng and P. ginseng were characterized, and were found to generate NgR1 and NgR2 by catalyzing the C6-O-Glc xylosylation of Rg1 and Rh1, respectively. Using one of these UGTs, PgUGT94Q13, and the previously identified PgUGT71A53 and PgUGT71A54, the biosynthetic pathway to produce saponins NgR1 and NgR2 from PPT could be available. The NgR1 cell factory was further developed by introducing PgUGT94Q13 and a heterologous UDP-xylose biosynthetic pathway from Arabidopsis thaliana into the highest Rg1-producing cell factory. The NgR2-producing cell factory was constructed by introducing PgUGT71A54, PgUGT94Q13, and the UDP-xylose biosynthetic pathway into the PPT chassis. De novo production of NgR1 and NgR2 reached 1.62 g/L and 1.25 g/L, respectively. Beyond the realization of artificial production of the three valuable saponins Rg1, NgR1, and NgR2 from glucose, our work provides a green and sustainable platform for the efficient production of other PPT-type saponins in engineered yeast strains, and promotes the industrial application of PPT-type saponins as medicine and functional foods.

CGT-seq: epigenome-guided de novo assembly of the core genome for divergent populations with large genome.

Genetic diversity in plants is remarkably high. Recent whole genome sequencing (WGS) of 67 rice accessions recovered 10,872 novel genes. Comparison of the genetic architecture among divergent populations or between crops and wild relatives is essential for obtaining functional components determining crucial traits. However, many major crops have gigabase-scale genomes, which are not well-suited to WGS. Existing cost-effective sequencing approaches including re-sequencing, exome-sequencing and restriction enzyme-based methods all have difficulty in obtaining long novel genomic sequences from highly divergent population with large genome size. The present study presented a reference-independent core genome targeted sequencing approach, CGT-seq, which employed epigenomic information from both active and repressive epigenetic marks to guide the assembly of the core genome mainly composed of promoter and intragenic regions. This method was relatively easily implemented, and displayed high sensitivity and specificity for capturing the core genome of bread wheat. 95% intragenic and 89% promoter region from wheat were covered by CGT-seq read. We further demonstrated in rice that CGT-seq captured hundreds of novel genes and regulatory sequences from a previously unsequenced ecotype. Together, with specific enrichment and sequencing of regions within and nearby genes, CGT-seq is a time- and resource-effective approach to profiling functionally relevant regions in sequenced and non-sequenced populations with large genomes.

Electroluminescence of ordered ZnO nanorod array/p-GaN light-emitting diodes with graphene current spreading layer.

Ordered ZnO nanorod array/p-GaN heterojunction light-emitting diodes (LEDs) have been fabricated by introducing graphene as the current spreading layer, which exhibit improved electroluminescence performance by comparison to the LED using a conventional structure (indium-tin-oxide as the current spreading layer). In addition, by adjusting the diameter of ZnO nanorod array in use, the light emission of the ZnO nanorod array/p-GaN heterojunction LEDs was enhanced further. This work has great potential applications in solid-state lighting, high performance optoelectronic devices, and so on. PACS: 78.60.Fi; 85.60.Jb; 78.67.Lt; 81.10.Dn.