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Bioresource Technology Jun 20242-Phenylethanol, known for its rose-like odor and antibacterial activity, is synthesized via exogenous phenylpyruvate by the sequential reaction of phenylpyruvate...
2-Phenylethanol, known for its rose-like odor and antibacterial activity, is synthesized via exogenous phenylpyruvate by the sequential reaction of phenylpyruvate decarboxylase (PDC) and aldehyde reductase. We first targeted ARO10, a phenylpyruvate decarboxylase gene from Saccharomyces cerevisiae, and identified a suitable aldehyde reductase gene. Co-expression of ARO10 and yahK in E. coli transformants yielded 1.1 g/L of 2-phenylethanol in batch culture. We hypothesized that there might be a bottleneck in PDC activity. The computer-based enzyme evolution was utilized to enhance production. The introduction of an amino acid substitution in ARO10 (ARO10 I544W) stabilized the aromatic ring of the phenylpyruvate substrate, increasing 2-phenylethanol yield 4.1-fold compared to wild-type ARO10. Cultivation of ARO10 I544W-expressing E. coli produced 2.5 g/L of 2-phenylethanol with a yield from glucose of 0.16 g/g after 72 h. This approach represents a significant advancement, achieving the highest yield of 2-phenylethanol from glucose using microbes to date.
PubMed: 38830477
DOI: 10.1016/j.biortech.2024.130927 -
Bioresources and Bioprocessing May 2024Dodecanedioic acid (DDA), a typical medium-chain dicarboxylic fatty acid with widespread applications, has a great synthetic value and a huge industrial market demand....
BACKGROUND
Dodecanedioic acid (DDA), a typical medium-chain dicarboxylic fatty acid with widespread applications, has a great synthetic value and a huge industrial market demand. Currently, a sustainable, eco-friendly and efficient process is desired for dodecanedioic acid production.
RESULTS
Herein, a multi-enzymatic cascade was designed and constructed for the production of DDA from linoleic acid based on the lipoxygenase pathway in plants. The cascade is composed of lipoxygenase, hydroperoxide lyase, aldehyde dehydrogenase, and unidentified double-bond reductase in E. coli for the main cascade reactions, as well as NADH oxidase for cofactor recycling. The four component enzymes involved in the cascade were co-expressed in E. coli, together with the endogenous double-bond reductase of E. coli. After optimizing the reaction conditions of the rate-limiting step, 43.8 g L d of DDA was obtained by a whole-cell one-pot process starting from renewable linoleic acid.
CONCLUSIONS
Through engineering of the reaction system and co-expressing the component enzymes, a sustainable and eco-friendly DDA biosynthesis route was set up in E. coli, which afforded the highest space time yield for DDA production among the current artificial multi-enzymatic routes derived from the LOX-pathway, and the productivity achieved here ranks the second highest among the current research progress in DDA biosynthesis.
PubMed: 38780695
DOI: 10.1186/s40643-024-00770-8 -
Pharmacology & Therapeutics Jul 2024Acute myocardial infarction (AMI) remains a leading cause of death worldwide. Increased formation of reactive oxygen species (ROS) during the early reperfusion phase is... (Review)
Review
Acute myocardial infarction (AMI) remains a leading cause of death worldwide. Increased formation of reactive oxygen species (ROS) during the early reperfusion phase is thought to trigger lipid peroxidation and disrupt redox homeostasis, leading to myocardial injury. Whilst the mitochondrial enzyme aldehyde dehydrogenase 2 (ALDH2) is chiefly recognised for its central role in ethanol metabolism, substantial experimental evidence suggests an additional cardioprotective role for ALDH2 independent of alcohol intake, which mitigates myocardial injury by detoxifying breakdown products of lipid peroxidation including the reactive aldehydes, malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE). Epidemiological evidence suggests that an ALDH2 mutant variant with reduced activity that is highly prevalent in the East Asian population increases AMI risk. Additional studies have uncovered a strong association between coronary heart disease and this ALDH2 mutant variant. It appears this enzyme polymorphism (in particular, in ALDH2*2/2 carriers) has the potential to have wide-ranging effects on thiol reactivity, redox tone and therefore numerous redox-related signaling processes, resilience of the heart to cope with lifestyle-related and environmental stressors, and the ability of the whole body to achieve redox balance. In this review, we summarize the journey of ALDH2 from a mitochondrial reductase linked to alcohol metabolism, via pre-clinical studies aimed at stimulating ALDH2 activity to reduce myocardial injury to clinical evidence for its protective role in the heart.
Topics: Humans; Aldehyde Dehydrogenase, Mitochondrial; Oxidation-Reduction; Myocardial Infarction; Animals; Ethanol; Polymorphism, Genetic; Aldehyde Dehydrogenase; Reactive Oxygen Species
PubMed: 38763322
DOI: 10.1016/j.pharmthera.2024.108666 -
Biotechnology For Biofuels and... May 2024Vanillin is a flavoring substance derived from vanilla. We are currently developing a biotransformation method for vanillin production using glucose. This report...
BACKGROUND
Vanillin is a flavoring substance derived from vanilla. We are currently developing a biotransformation method for vanillin production using glucose. This report describes the last step in vanillin production: the conversion of vanillic acid to vanillin. First, we selected Corynebacterium glutamicum as the host owing to its high vanillin resistance. The aromatic aldehyde reductase gene (NCgl0324) and vanillic acid demethylase protein subunits A and B gene (vanAB, NCgl2300-NCgl2301) were deleted in C. glutamicum genome to avoid vanillin degradation. Next, we searched for an aromatic carboxylic acid reductase (ACAR), which converts vanillic acid to vanillin. Seventeen ACAR homologs from various organisms were introduced into C. glutamicum.
RESULTS
In vivo conversion experiments showed that eight ACARs were successfully expressed and produced vanillin. In terms of conversion activity and substrate specificity, the ACARs from Gordonia effusa, Coccomyxa subellipsoidea, and Novosphingobium malaysiense are promising candidates for commercial production.
CONCLUSIONS
Corynebacterium glutamicum harboring Gordonia effusa ACAR produced 22 g/L vanillin, which is, to the best of our knowledge, the highest accumulation reported in the literature. At the same time, we discovered ACAR from Novosphingobium malaysiense and Coccomyxa subellipsoidea C-169 with high substrate specificity. These findings are useful for reducing the byproducts.
PubMed: 38693567
DOI: 10.1186/s13068-024-02507-3 -
Oncology Research 2024Bortezomib results in peripheral neuropathy (PN) in approximately 50% of patients, during multiple myeloma (MM) treatment, a complication known as Bortezomib-induced...
BACKGROUND
Bortezomib results in peripheral neuropathy (PN) in approximately 50% of patients, during multiple myeloma (MM) treatment, a complication known as Bortezomib-induced peripheral neuropathy (BIPN). The drug response varies among individuals. Genetic factor may play an important role in BIPN.
METHODS
A next-generation sequencing (NGS) panel containing 1659 targets from 233 genes was used to identify risk variants for developing BIPN in 204 MM patients who received bortezomib therapy. mRNA expression of and in 62 peripheral blood samples was detected by real-time quantitative PCR (RT-qPCR). Serum homocysteine (Hcy) levels were detected in 40 samples by chemiluminescent microparticle immunoassay (CMIA).
RESULTS
Compared with the non-BIPN group (n = 89), a total of 8 significantly associated single nucleotide polymorphisms (SNPs) were identified in the BIPN group (n = 115): (rs1801131, rs1801133, rs17421511), (rs1051740), (rs2016848), (rs6151031), (rs1935349) and (rs8192720). The mRNA expression level of in newly diagnosed patients with peripheral neuritis after treatment (NP group) was lower than that of newly diagnosed patients without peripheral neuritis after treatment (NnP group) (1.70 ± 0.77 . 2.81 ± 0.97, = 0.009). Serum Hcy levels were significantly higher in BIPN group than in non-BIPN group (11.66 ± 1.79 μmol/L . 8.52 ± 3.29 μmol/L, = 0.016) and healthy controls (11.66 ± 1.79 μmol/L . 8.55 ± 2.13 μmol/L, ≤ 0.001).
CONCLUSION
and BIPN are linked in Chinese MM patients. BIPN is more likely to occur in patients with lower mRNA expression, which might result in higher serum Hcy levels.
Topics: Humans; Bortezomib; Peripheral Nervous System Diseases; Male; Female; Middle Aged; Polymorphism, Single Nucleotide; Multiple Myeloma; Aged; Methylenetetrahydrofolate Reductase (NADPH2); Asian People; Aldehyde Dehydrogenase 1 Family; Antineoplastic Agents; Retinal Dehydrogenase; Genetic Predisposition to Disease; Adult; China; High-Throughput Nucleotide Sequencing; East Asian People
PubMed: 38686049
DOI: 10.32604/or.2023.043922 -
ELife Apr 2024Metabolism and biological functions of the nitrogen-rich compound guanidine have long been neglected. The discovery of four classes of guanidine-sensing riboswitches and...
Metabolism and biological functions of the nitrogen-rich compound guanidine have long been neglected. The discovery of four classes of guanidine-sensing riboswitches and two pathways for guanidine degradation in bacteria hint at widespread sources of unconjugated guanidine in nature. So far, only three enzymes from a narrow range of bacteria and fungi have been shown to produce guanidine, with the ethylene-forming enzyme (EFE) as the most prominent example. Here, we show that a related class of Fe- and 2-oxoglutarate-dependent dioxygenases (2-ODD-C23) highly conserved among plants and algae catalyze the hydroxylation of homoarginine at the C6-position. Spontaneous decay of 6-hydroxyhomoarginine yields guanidine and 2-aminoadipate-6-semialdehyde. The latter can be reduced to pipecolate by pyrroline-5-carboxylate reductase but more likely is oxidized to aminoadipate by aldehyde dehydrogenase ALDH7B . Arabidopsis has three 2-ODD-C23 isoforms, among which Din11 is unusual because it also accepted arginine as substrate, which was not the case for the other 2-ODD-C23 isoforms from Arabidopsis or other plants. In contrast to EFE, none of the three Arabidopsis enzymes produced ethylene. Guanidine contents were typically between 10 and 20 nmol*(g fresh weight) in Arabidopsis but increased to 100 or 300 nmol*(g fresh weight) after homoarginine feeding or treatment with Din11-inducing methyljasmonate, respectively. In 2-ODD-C23 triple mutants, the guanidine content was strongly reduced, whereas it increased in overexpression plants. We discuss the implications of the finding of widespread guanidine-producing enzymes in photosynthetic eukaryotes as a so far underestimated branch of the bio-geochemical nitrogen cycle and propose possible functions of natural guanidine production.
Topics: Guanidine; Mixed Function Oxygenases; Homoarginine; Arabidopsis; Guanidines; Protein Isoforms; 2-Aminoadipic Acid
PubMed: 38619227
DOI: 10.7554/eLife.91458 -
Microorganisms Mar 20243,4-Dichloroaniline (34DCA), a major metabolite of phenylurea herbicides, causes environmental contamination owing to its toxicity and recalcitrant properties. strain...
3,4-Dichloroaniline (34DCA), a major metabolite of phenylurea herbicides, causes environmental contamination owing to its toxicity and recalcitrant properties. strain GFJ2, isolated from soil potentially contaminated with herbicides, can degrade 34DCA. This study aimed to identify and characterize the 34DCA degradation gene cluster responsible for the conversion of 34DCA to 4,5-dichlorocatechol in the strain GFJ2. Genome analysis revealed one chromosome and seven plasmids in GFJ2, comprising 21, 75, and 3309 copies of rRNA, 75 tRNA, and protein-encoding genes, respectively. A gene cluster responsible for 34DCA degradation was identified, comprising , , and , which encode dioxygenase, flavin reductase, and aldehyde dehydrogenase, respectively. Transcriptional analysis indicated that this gene cluster is constructed as an operon, induced during 34DCA utilization. The heterologous expression of and in confirmed their activity in degrading 34DCA to an intermediate metabolite, converted to 4,5-dichlorocatechol via a reaction involving the gene product, suggesting their involvement in 34DCA conversion to 4,5-dichlorocatechol. Deletion mutants of and lost 34DCA degradation ability, confirming their importance in 34DCA utilization in GFJ2. This study provides insights into the genetic mechanisms of 34DCA degradation by GFJ2, with potential applications in the bioremediation of environments contaminated by phenylurea herbicides.
PubMed: 38543664
DOI: 10.3390/microorganisms12030613 -
Antioxidants (Basel, Switzerland) Jan 2024Bone marrow cells are the most sensitive to exposure to X-rays in the body and are selectively damaged even by doses that are generally considered permissive in other...
Bone marrow cells are the most sensitive to exposure to X-rays in the body and are selectively damaged even by doses that are generally considered permissive in other organs. Ascorbic acid (Asc) is a potent antioxidant that is reported to alleviate damages caused by X-ray exposure. However, rodents can synthesize Asc, which creates difficulties in rigorously assessing its effects in such laboratory animals. To address this issue, we employed mice with defects in their ability to synthesize Asc due to a genetic ablation of aldehyde reductase (-KO). In this study, concentrations of white blood cells (WBCs) were decreased 3 days after exposure to X-rays at 2 Gy and then gradually recovered. At approximately one month, the recovery rate of WBCs was delayed in the -KO mouse group, which was reversed via supplementation with Asc. Following exposure to X-rays, Asc levels decreased in plasma, bone marrow cells, and the liver during an early period, and then started to increase. X-ray exposure stimulated the pituitary gland to release adrenocorticotropic hormone (ACTH), which stimulated corticosterone secretion. Asc released from the liver, which was also stimulated by ACTH, appeared to be recruited to the bone marrow. Since corticosterone in high doses is injurious, these collective results imply that Asc protects bone marrow via its antioxidant capacity against ROS produced via exposure to X-rays and the cytotoxic action of transiently elevated corticosterone.
PubMed: 38397750
DOI: 10.3390/antiox13020152 -
International Journal of Molecular... Feb 2024The employment of 2-deoxyribose-5-phosphate aldolase (DERA) stands as a prevalent biocatalytic route for synthesizing statin side chains. The main problem with this...
The employment of 2-deoxyribose-5-phosphate aldolase (DERA) stands as a prevalent biocatalytic route for synthesizing statin side chains. The main problem with this pathway is the low stability of the enzyme. In this study, mesocellular silica foam (MCF) with different pore sizes was used as a carrier for the covalent immobilization of DERA. Different functionalizing and activating agents were tested and kinetic modeling was subsequently performed. The use of succinic anhydride as an activating agent resulted in an enzyme hyperactivation of approx. 140%, and the stability almost doubled compared to that of the free enzyme. It was also shown that the pore size of MCF has a decisive influence on the stability of the DERA enzyme.
Topics: Hydroxymethylglutaryl-CoA Reductase Inhibitors; Silicon Dioxide; Aldehyde-Lyases; Fructose-Bisphosphate Aldolase; Biocatalysis
PubMed: 38396648
DOI: 10.3390/ijms25041971 -
Cell & Bioscience Feb 2024The development of alcohol-associated liver disease (ALD) is influenced by the amount and duration of alcohol consumption. The resulting liver damage can range from...
BACKGROUND
The development of alcohol-associated liver disease (ALD) is influenced by the amount and duration of alcohol consumption. The resulting liver damage can range from reversible stages, such as steatosis, steatohepatitis and alcoholic fibrosis, to the advanced and irreversible stage of cirrhosis. Aldo-keto reductase family 1 member A1 (AKR1A1) is a member of the aldo-keto reductase family that catalyzes the reduction of aldehyde groups to their corresponding alcohols in an NADPH-dependent manner. AKR1A1 was found to be downregulated in patients diagnosed with ALD. This study aims to interpret the protective effects of AKR1A1 on the development of ALD.
METHODS
A 5% alcohol-fed (AF) Akr1a1 knockout (Akr1a1) mouse model and an AML12 hepatocyte model were used. The effects of AKR1A1 on liver function, inflammation, oxidative stress, lipid accumulation, and fibrosis were assessed by ELISA, western blotting, RT‒PCR, and a variety of histological staining methods in AF-induced wild-type (WT) and Akr1a1 mice compared to control liquid diet-fed (PF) WT and Akr1a1 mice.
RESULTS
The results demonstrated that AF-WT mice expressed higher levels of AKR1A1 than WT mice fed a control diet, and they did not show any noticeable liver steatosis. However, AF-Akr1a1 mice displayed a lower survival rate and more severe liver injury than AF-WT mice, as demonstrated by increased proinflammatory cytokines, oxidative stress, lipid accumulation, fibrosis, and reduced antioxidant enzymes in their livers. Additionally, elevated levels of 4-HNE and p53 phosphorylation were observed in AF-Akr1a1 mice, suggesting that the loss of AKR1A1 led to increased 4-HNE accumulation and subsequent activation of p53, which contributed to the progression of ALD. Furthermore, in AML12 hepatocytes, Akr1a1 knockdown aggravated oxidative stress and steatosis induced by palmitic acid/oleic acid (P/O) inflammation induced by lipopolysaccharide (LPS), and fibrosis induced by TGF-β1.
CONCLUSIONS
This loss-of-function study suggests that AKR1A1 plays a liver-protective role during chronic alcohol consumption by reducing the accumulation of 4-HNE and inhibiting 4-HNE-mediated p53 activation.
PubMed: 38308335
DOI: 10.1186/s13578-024-01200-0