This study aims to investigate the mechanism of Qingrun Decoction in alleviating hepatic insulin resistance in type 2 diabetes mellitus(T2DM) rats through the reprogramming of amino acid metabolism. A T2DM rat model was established by inducing insulin resistance through a high-fat diet combined with intraperitoneal injection of streptozotocin. The model rats were randomly divided into five groups: model group, high-, medium-, and low-dose Qingrun Decoction groups, and metformin group. A normal control group was also established. The rats in the normal and model groups received 10 mL·kg~(-1) distilled water daily by gavage. The metformin group received 150 mg·kg~(-1) metformin suspension by gavage, and the Qingrun Decoction groups received 11.2, 5.6, and 2.8 g·kg~(-1) Qingrun Decoction by gavage for 8 weeks. Blood lipid levels were measured in different groups of rats. Pathological damage in rat liver tissue was assessed by hematoxylin-eosin(HE) staining and oil red O staining. Transcriptome sequencing and untargeted metabolomics were performed on rat liver and serum samples, integrated with bioinformatics analyses. Key metabolites(branched-chain amino acids, BCAAs), amino acid transporters, amino acid metabolites, critical enzymes for amino acid metabolism, resistin, adiponectin(ADPN), and mammalian target of rapamycin(mTOR) pathway-related molecules were quantified using quantitative real-time polymerase chain reaction(qRT-PCR), Western blot, and enzyme-linked immunosorbent assay(ELISA). The results showed that compared with the normal group, the model group had significantly increased serum levels of total cholesterol(TC), triglycerides(TG), low-density lipoprotein cholesterol(LDL-C), and resistin and significantly decreased ADPN levels. Hepatocytes in the model group exhibited loose arrangement, significant lipid accumulation, fatty degeneration, and pronounced inflammatory cell infiltration. In liver tissue, the mRNA transcriptional levels of solute carrier family 7 member 2(Slc7a2), solute carrier family 38 member 2(Slc38a2), solute carrier family 38 member 4(Slc38a4), and arginase(ARG) were significantly downregulated, while the mRNA transcriptional levels of solute carrier family 1 member 4(Slc1a4), solute carrier family 16 member 1(Slc16a1), and methionine adenosyltransferase(MAT) were upregulated. Furthermore, the mRNA transcription and protein expression levels of branched-chain α-keto acid dehydrogenase E1α(BCKDHA) and DEP domain-containing mTOR-interacting protein(DEPTOR) were downregulated, while mRNA transcription and protein expression levels of mTOR, as well as ribosomal protein S6 kinase 1(S6K1), were upregulated. The levels of BCAAs and S-adenosyl-L-methionine(SAM) were elevated. The serum level of 6-hydroxymelatonin was significantly reduced, while imidazole-4-one-5-propionic acid and N-(5-phospho-D-ribosyl)anthranilic acid levels were significantly increased. Compared with the model group, Qingrun Decoction significantly reduced blood lipid and resistin levels while increasing ADPN levels. Hepatocytes had improved morphology with reduced inflammatory cells, and fatty degeneration and lipid deposition were alleviated. Differentially expressed genes and differential metabolites were mainly enriched in amino acid metabolic pathways. The expression levels of Slc7a2, Slc38a2, Slc38a4, and ARG in the liver tissue were significantly upregulated, while Slc1a4, Slc16a1, and MAT expression levels were significantly downregulated. BCKDHA and DEPTOR expression levels were upregulated, while mTOR and S6K1 expression levels were downregulated. Additionally, the levels of BCAAs and SAM were significantly decreased. The serum level of 6-hydroxymelatonin was increased, while those of imidazole-4-one-5-propionic acid and N-(5-phospho-D-ribosyl)anthranilic acid were decreased. In summary, Qingrun Decoction may improve amino acid metabolism reprogramming, inhibit mTOR pathway activation, alleviate insulin resistance in the liver, and mitigate pathological damage of liver tissue in T2DM rats by downregulating hepatic BCAAs and SAM and regulating key enzymes involved in amino acid metabolism, such as BCKDHA, ARG, and MAT, as well as amino acid metabolites and transporters.
Animals ; Drugs, Chinese Herbal/administration & dosage* ; Rats ; Insulin Resistance ; Diabetes Mellitus, Type 2/genetics* ; Male ; Liver/drug effects* ; Amino Acids/metabolism* ; Rats, Sprague-Dawley ; Humans ; Metabolic Reprogramming

Hydroxyectoine, a vital compatible solute, is widely utilized in cosmetics, food, pharmaceutical industries, and biologics. However, the current microbial fermentation methods for hydroxyectoine production face challenges including insufficient precursor supply and low yields. Therefore, developing engineering microbial strains capable of efficiently synthesizing hydroxyectoine is of great significance. In this study, we first constructed a high-yield ectoine-producing strain ECT04 by multi-copy integration of the ectoine synthesis genes ectABC into the pseudogene loci of Escherichia coli MG1655(DE3), achieving an ectoine titer of 6.03 g/L. Subsequently, we employed plasmids with varying copy numbers to express ectD from Chromohalobacter salexigens to enable the conversion for hydroxyectoine production. We further investigated the effects of promoter, co-substrate ɑ-ketoglutarate, Fe²⁺ concentration, and dissolved oxygen on hydroxyectoine synthesis. Through fed-batch fermentation in a 7-L bioreactor, we significantly enhanced the hydroxyectoine production efficiency, attaining a final titer of 8.58 g/L and a productivity of 0.24 g/(L·h). This work successfully achieved the de novo synthesis of hydroxyectoine in E. coli, laying a foundation for the efficient bioproduction of this compound.
Escherichia coli/genetics* ; Fermentation ; Amino Acids, Diamino/biosynthesis* ; Bioreactors/microbiology* ; Metabolic Engineering/methods* ; Chromohalobacter/genetics* ; Plasmids/genetics*

WRKYs is a unique family of transcription factors (TFs) in plants, and belongs to the typical multifunctional regulator. It is involved in the regulation of multiple signaling pathways. This type of transcription factor is characterized to contain about 60 highly conservative amino acids as the WRKY domain, and usually also has the Cys2His2 or Cys2His-Cys zinc finger structure. WRKYs can directly bind to the W-box sequence ((T)(T) TGAC (C/T)) in the promoter region of the downstream target gene, and activate or inhibit the transcription of the target genes by interacting with the target protein. They may up-regulate the expression of stress-related genes through integrating signal pathways mediated by abscisic acid (ABA) and reactive oxygen species (ROS), thus playing a vital role in regulating plant response to abiotic stresses. This review summarizes the advances in research on the structure and classification, regulatory approach of WRKYs, and the molecular mechanisms of WRKYs involved in response to drought and salt stresses, and prospects future research directions, with the aim to provide a theoretical support for the genetic improvement of crop in response to abiotic stresses.
Transcription Factors/genetics* ; Abscisic Acid ; Amino Acids ; Droughts ; Stress, Physiological/genetics*

ω-transaminases are able to catalyze the reversible transfer of amino groups between diverse amino compounds (such as amino acids, alkyl amines, aromatic amines) and carbonyl compounds (such as aldehydes, ketones, ketoacids). ω-transaminases exhibit great application prospects in the field of chiral amine biosynthesis because of their desirable properties, such as wide range of substrates, high stereoselectivity, and mild catalytic conditions. It is therefore important for China to develop efficient, specific, and environment-friendly chiral amine production technologies with independent intellectual property rights, which is of great significance for the development of pharmaceutical, pesticide, and material industries. This review systematically summarizes the Chinese patents regarding ω-transaminase filed by Chinese institutions in the recent decade. The development of ω-transaminase resource, enzymatic property improvement by protein engineering, application in chiral amine synthesis, and development of production technologies are elaborated. This review will shed light on further basic and application studies of ω-transaminase.
Transaminases/genetics* ; Amino Acids ; China ; Aldehydes ; Amines

As a branched chain amino acid, L-valine is widely used in the medicine and feed sectors. In this study, a microbial cell factory for efficient production of L-valine was constructed by combining various metabolic engineering strategies. First, precursor supply for L-valine biosynthesis was enhanced by strengthening the glycolysis pathway and weakening the metabolic pathway of by-products. Subsequently, the key enzyme in the L-valine synthesis pathway, acetylhydroxylate synthase, was engineered by site-directed mutation to relieve the feedback inhibition of the engineered strain. Moreover, promoter engineering was used to optimize the gene expression level of key enzymes in L-valine biosynthetic pathway. Furthermore, cofactor engineering was adopted to change the cofactor preference of acetohydroxyacid isomeroreductase and branched-chain amino acid aminotransferase from NADPH to NADH. The engineered strain C. glutamicum K020 showed a significant increase in L-valine titer, yield and productivity in 5 L fed-batch bioreactor, up to 110 g/L, 0.51 g/g and 2.29 g/(L‧h), respectively.
Valine ; Corynebacterium glutamicum/genetics* ; Metabolic Engineering ; Amino Acids, Branched-Chain ; Bioreactors

Objective: To investigate the relationship between amino acid variations of respiratory syncytial virus (RSV) nonstructural protein (NS) 1 and the clinical characteristics. Method: A retrospective case review was conducted. From December 2018 to January 2020, a total of 81 cases of hospitalized children who were tested only positive for RSV by RT-PCR or PCR at the Department of Respiratory Medicine, Children's Hospital of Chongqing Medical University were included in the study. The NS1 genes of RSV subtype A and subtype B were amplified by PCR and sequenced. The amino acid sequences were analyzed. The Chi-square test and Mann-Whitney rank sum test were used to compare the clinical characteristics and type Ⅰ interferon levels of children with or without NS1 variation in the variation and non-variation groups. Results: Among 81 cases, there were 58 males and 23 females. There were 11 cases in the variation group, the age of onset was 2.0 (1.0, 11.0) months, included 4 cases of subtype A (variant sites were: 2 cases for Lys33Gln, one case for Gly2Asp, Pro67Ser, Leu137Phe, respectively) and 7 cases of subtype B (variant sites were: two cases for Val121Ile, one case for Tyr30Cys, Val65Met, Asn85Ser, Ser118Asn, Asp124Asn, respectively). These variant sites all appeared at a very low frequency 0.08 (0.04, 0.29) % in the NCBI PROTEIN database. There were 70 cases in non-variation group, the onset age was 3.5 (1.0, 7.0) months. The proportion of dyspnea in the variation group was higher than that in the non-variation group (10/11 vs. 47% (33/70), χ²=7.31, P<0.01). Conclusions: There are some variant sites in nonstructural protein NS1 of RSV. Children may be prone to have dyspnea with NS1 variations.
Child ; Male ; Female ; Humans ; Infant ; Respiratory Syncytial Virus Infections ; Amino Acids ; Retrospective Studies ; Respiratory Syncytial Virus, Human/genetics* ; Polymerase Chain Reaction

The α-amino acid ester acyltransferase (SAET) from Sphingobacterium siyangensis is one of the enzymes with the highest catalytic ability for the biosynthesis of l-alanyl-l-glutamine (Ala-Gln) with unprotected l-alanine methylester and l-glutamine. To improve the catalytic performance of SAET, a one-step method was used to rapidly prepare the immobilized cells (SAET@ZIF-8) in the aqueous system. The engineered Escherichia coli (E. coli) expressing SAET was encapsulated into the imidazole framework structure of metal organic zeolite (ZIF-8). Subsequently, the obtained SAET@ZIF-8 was characterized, and the catalytic activity, reusability and storage stability were also investigated. Results showed that the morphology of the prepared SAET@ZIF-8 nanoparticles was basically the same as that of the standard ZIF-8 materials reported in literature, and the introduction of cells did not significantly change the morphology of ZIF-8. After repeated use for 7 times, SAET@ZIF-8 could still retain 67% of the initial catalytic activity. Maintained at room temperature for 4 days, 50% of the original catalytic activity of SAET@ZIF-8 could be retained, indicating that SAET@ZIF-8 has good stability for reuse and storage. When used in the biosynthesis of Ala-Gln, the final concentration of Ala-Gln reached 62.83 mmol/L (13.65 g/L) after 30 min, the yield reached 0.455 g/(L·min), and the conversion rate relative to glutamine was 62.83%. All these results suggested that the preparation of SAET@ZIF-8 is an efficient strategy for the biosynthesis of Ala-Gln.
Escherichia coli/genetics* ; Glutamine ; Zeolites/chemistry* ; Amino Acids

OBJECTIVE: To retrospectively analyze the clinical phenotypes and genetic variants in two Chinese pedigrees affected with Hereditary hypofibrinemia (IFD) and explore their molecular pathogenesis. METHODS: Two probands and their pedigree members were admitted to the First Affiliated Hospital of Wenzhou Medical University on March 30, 2021 and May 27, 2021, respectively. Clinical phenotypes of the probands were collected, and blood clotting indexes of the probands and their pedigree members were determined. Variants of the FGA, FGB and FGG genes were analyzed by Sanger sequencing, and candidate variants were verified by sequence comparison. Bioinformatic software was used to analyze the conservation of the amino acids and pathogenicity of the proteins. Alteration in protein structure and intermolecular force before and after the variant was analyzed by simulating the protein model. RESULTS: Proband 1, a 18-year-old male, had significantly low plasma fibrinogen activity (Fg:C) and plasma fibrinogen antigen (Fg:Ag), respectively at 0.80 g/L and 1.00 g/L. Proband 2, a 43-year-old male, had slightly low Fg:C and Fg:Ag at 1.35 g/L and 1.30 g/L, respectively. The Fg:C and Fg:Ag of proband 1's father, proband 2's father and son were also below the normal level. Genetic testing showed that proband 1 had harbored a heterozygous missense variant of c.688T>G (p.Phe230Val) in exon 7 of the FGG gene, which was inherited from his father. Proband 2, his father and son all had harbored a heterozygous variant of c.2516A>C (p.Asn839Thr) in exon 6 of the FGA gene. Homology analysis showed that the Phe230 and Asn839 residues were highly conserved among homologous species. Bioinformatic analysis predicted that both p.Phe230Val and p.Asn839Thr were pathogenic variants. CONCLUSION Analysis of protein simulation model showed that the p.Asn839Thr variant has changed the hydrogen bo`nd between the amino acids, thus affecting the stability of the protein structure. The heterozygous missense variants of p.Phe230Val and p.Asn839Thr probably underlay the IFD in the two pedigrees.
Humans ; Male ; Amino Acids ; East Asian People ; Exons ; Pedigree ; Retrospective Studies ; Afibrinogenemia/genetics* ; Mutation, Missense ; Fibrinogen/genetics*

Tanshinones are one of the main effective components of Salvia miltiorrhiza, which play important roles in the treatment of cardiovascular diseases. Microbial heterogony production of tanshinones can provide a large number of raw materials for the production of traditional Chinese medicine(TCM) preparations containing S. miltiorrhiza, reduce the extraction cost, and relieve the pressure of clinical medication. The biosynthetic pathway of tanshinones contains multiple P450 enzymes, and the catalytic element with high efficiency is the basis of microbial production of tanshinones. In this study, the protein modification of CYP76AK1, a key P450-C20 hydroxylase in tanshinone pathway, was researched. The protein modeling methods SWISS-MODEL, Robetta, and AlphaFold2 were used, and the protein model was analyzed to obtain the reliable protein structure. The semi-rational design of mutant protein was carried out by molecular docking and homologous alignment. The key amino acid sites affecting the oxidation activity of CYP76AK1 were identified by molecular docking. The function of the obtained mutations was studied with yeast expression system, and the CYP76AK1 mutations with continuous oxidation function to 11-hydroxysugiol were obtained. Four key amino acid sites that affected the oxidation acti-vity were analyzed, and the reliability of three protein modeling methods was analyzed according to the mutation results. The effective protein modification sites of CYP76AK1 were reported for the first time in this study, which provides a catalytic element for different oxidation activities at C20 site for the study of the synthetic biology of tanshinones and lays a foundation for the analysis of the conti-nuous oxidation mechanism of P450-C20 modification.
Oxidoreductases ; Biosynthetic Pathways ; Molecular Docking Simulation ; Reproducibility of Results ; Salvia miltiorrhiza/chemistry* ; Amino Acids/metabolism* ; Plant Roots/genetics*

This study aimed to demonstrate the effect of Banxia Baizhu Tianma Decoction(BBTD) on realizing withdrawal of anti-epileptic drugs and explore the relationship between BBTD and the amino acid metabolism by transcriptomic analysis in the rat model of epilepsy induced by lithium chloride-pilocarpine. The rats with epilepsy were divided into a control group(Ctrl), an epilepsy group(Ep), a BBTD & antiepileptic drug integrative group(BADIG), and an antiepileptic drug withdrawal group(ADWG). The Ctrl and Ep were given ultrapure water by gavage for 12 weeks. The BADIG was given BBTD extract and carbamazepine solution by gavage for 12 weeks. The ADWG was given carbamazepine solution and BBTD extract by gavage for the former 6 weeks, and then only given BBTD extract for the latter 6 weeks. The therapeutic effect was evaluated by behavioral observation, electroencephalogram(EEG), and hippocampal neuronal morphological changes. High-throughput sequencing was used to obtain amino acid metabolism-related differen-tial genes in the hippocampus, and the mRNA expression in the hippocampus of each group was verified by real-time quantitative polymerase chain reaction(RT-qPCR). The hub genes were screened out through protein-protein interaction(PPI) network, and Gene Ontology(GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis were performed. Two ceRNA networks, namely circRNA-miRNA-mRNA and lncRNA-miRNA-mRNA, were constructed for ADWG vs BADIG. The experimental results showed that compared with those in Ep, rats in ADWG were significantly improved in the behavioral observation, EEG, and hippocampal neuronal impairment. Thirty-four amino acid metabolism-related differential genes were obtained by transcriptomic analysis, and the sequencing results were confirmed by RT-qPCR. Eight hub genes were obtained through PPI network, involving several biological processes, molecular functions, and signal pathways related to amino acid metabolism. Finally, the circRNA-miRNA-mRNA ternary transcription network of 17 circRNA, 5 miRNA, and 2 mRNA, and a lncRNA-miRNA-mRNA ternary network of 10 lncRNA, 5 miRNA, and 2 mRNA were constructed in ADWG vs BADIG. In conclusion, BBTD can effectively achieve the withdrawal of antiepileptic drugs, which may be related to the transcriptomic regulation of amino acid metabolism.
Rats ; Animals ; RNA, Circular/genetics* ; Transcriptome ; RNA, Long Noncoding/genetics* ; Anticonvulsants ; MicroRNAs/genetics* ; RNA, Messenger ; Carbamazepine ; Amino Acids ; Gene Regulatory Networks