Background: Isoliquiritigenin, a key pharmacologically active compound derived from the traditional Chinese medicine Glycyrrhizae Radix et Rhizoma, can be further modified into various high-value 5-deoxyflavones, demonstrating significant potential for pharmaceutical development. Currently, the supply of isoliquiritigenin primarily depends on plant extraction. However, heterologous synthesis using microbial cell factories presents a promising alternative, offering a solution to resource limitations caused by the dwindling availability of Glycyrrhiza uralensis. Objective: This study aimed to employ heterologous synthesis in yeast strains for the stable and high-efficiency production of isoliquiritigenin. Methods: First, a stable chassis strain for isoliquiritigenin production was constructed by integrating optimized biosynthetic pathway enzyme genes. A type IV noncatalytic chalcone isomerase-like protein and a synthetic protein scaffold system were employed to enhance the metabolic channeling of key pathway enzymes. Subsequently, yeast metabolism was fine-tuned to balance precursor supply, and cofactor engineering strategies were implemented to increase nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) availability, thereby ensuring the catalytic efficiency of the key enzyme chalcone reductase. Results: The engineered strain Y21-2 achieved a 24.4-fold increase in isoliquiritigenin titer compared to the original strain. Additionally, the proportion of the by-product naringenin chalcone was reduced by 67.8%, marking the first instance in which the ratio of C-5 hydroxylated by-products was minimized to 10.4% during the microbial synthesis of 5-deoxyflavones. Conclusion: This work provides a valuable reference for the efficient and sustainable production of isoliquiritigenin, laying a solid foundation for further pathway optimization and the biotechnological synthesis of other high-value natural 5-deoxyflavones.

Objective To express the protein enconded by the Rv3432c gene of Mycobacterium tuberculosis(M.tb)in vitro by prokaryotic expression,to analyze the structure of the Rv3432c protein by using bioinformatics software,and to explore for new drug targets against M.tb.Methods The Rv3432c gene was amplified by PCR using the genomic DNA of the inactivated M.tb strain H37Rv as the template and a recombinant plasmid was constructed with the expression vector pET-28a.The expression products were analyzed by SDS-PAGE and purified using affinity chromatography.The biological properties of Rv3432c were analyzed with Protparam,the Pfam online tool,SOMPA,Protscale,TMHMM Signalp 6.0,NetPhos3.1,SUMOsp 2.0,and SWISS-MODEL.Results pET-28a-Rv3432c recombinant plasmid sequencing results were fully consistent with those of the target gene.SDS-PAGE analysis showed that the fusion protein existed in the form of a soluble protein with a relative molecular mass of about 55×103,which matched the expected size.ProtParam analysis showed that the Rv3432c protein was hydrophilic(showing a GRAVY value of-0.079).Rv3432c was a protein with no transmembrane structural domains or signal peptide.The secondary structure of Rv3432c mainly consisted of random coils(39.78%)and α-helix(39.57%)and was relatively loosely structured.Conclusion We successfully constructed a prokaryotic expression plasmid of the Rv3432c protein and analyzed its structure using bioinformatics,laying the foundation for further research on the role of Rv3432c in the pathogenesis and progression of tuberculosis as well as the identification of new drug targets against M.tb.

China ; Humans ; Lenalidomide/therapeutic use* ; Multiple Myeloma/drug therapy* ; Thalidomide ; Therapeutic Equivalency

The UL49.5 gene of most herpesviruses is conserved and encodes glycoprotein N. However, the UL49.5 protein of duck enteritis virus (DEV) (pUL49.5) has not been reported. In the current study, the DEV pUL49.5 gene was first subjected to molecular characterization. To verify the predicted intracellular localization of gene expression, the recombinant plasmid pEGFP-C1/pUL49.5 was constructed and used to transfect duck embryo fibroblasts. Next, the recombinant plasmid pDsRed1-N1/glycoprotein M (gM) was produced and used for co-transfection with the pEGFP-C1/pUL49.5 plasmid to determine whether DEV pUL49.5 and gM (a conserved protein in herpesviruses) colocalize. DEV pUL49.5 was thought to be an envelope glycoprotein with a signal peptide and two transmembrane domains. This protein was also predicted to localize in the cytoplasm and endoplasmic reticulum with a probability of 66.7%. Images taken by a fluorescence microscope at different time points revealed that the DEV pUL49.5 and gM proteins were both expressed in the cytoplasm. Overlap of the two different fluorescence signals appeared 12 h after transfection and continued to persist until the end of the experiment. These data indicate a possible interaction between DEV pUL49.5 and gM.
Animals ; Ducks/virology ; Genes, Viral/genetics ; Mardivirus/*genetics ; Membrane Glycoproteins/*genetics ; Microscopy, Fluorescence ; Phylogeny ; Polymerase Chain Reaction/veterinary ; Viral Envelope Proteins/*genetics

Objective To explore the aesthetic efficacy of modified endoscopic rhytidectomy by using the techniques to minimize tissue damage,to obviate injury to the vessels and nerves,and to control bleeding and to firm fixation.Methods Two discontinuous incisions were made in the temporal scalp during the procedure,obviating injury to the branches of the superficial temporal vessels.Endoscopic technique was used to facilitate elevating,hemostasis,slinging and fixation in the plane under superficial temporal fascia.Three transverse incisions were made after the hairline in the forhead scalp,the operation was carried out by using endoscopic equipment,and the elevated forhead flap was slinged and fixed upward to the lamina externa cranii.Results 58 cases were received endoscopic forehead and temporal rhytidectomy,only slight edema was observed after surgery,and no obvisous ecchymosis was found.All patients returned home 7 days after operation.Degree of satisfaction on long-term follow-up showed that 56 cases(96.55%)improved obviously one year postoperatively;35 cases followed up 2 years,33(94.29%)of them improved obviously.None case was suffered from facial nerve injury.Conclusion The purpose of endoscopic rhytidectomy is to avoid carrying out the operation out of sight,to minimize unexpected damage to vessels and nerves,and to facilitate dissection,hemostasis,suturing,slingling and fixation.By refining the technique,we can achieve minimal injury,shorten recovery period,and obtain more satisfactory results,so the indication for operation is extended.