Project description:Medium- and branched-chain diols and amino alcohols are important industrial solvents, polymer building blocks, cosmetics and pharmaceutical ingredients, yet biosynthetically challenging to produce. Here, we present a novel approach utilising a modular polyketide synthase (PKS) platform for the efficient production of these compounds. This platform takes advantage of a versatile loading module from the rimocidin PKS and NADPH-dependent terminal thioreductases (TRs), previously untapped in engineered PKSs. Reduction of the terminal aldehyde with specific alcohol dehydrogenases enables production of diols, oxidation enables production of hydroxy acids, and transamination with specific transaminases enables production of various amino alcohols. Furthermore, replacement of the malonyl-coenzyme A (CoA)–specific acyltransferase (AT) in the extension module with methyl- or ethylmalonyl-CoA–specific ATs enables production of branched-chain diols and amino alcohols. In total, we demonstrated production of nine 1,3-diols (including the difficult-to-produce insect repellent and cosmetic ingredient 2-ethyl-1,3-hexanediol), six amino alcohols, and two carboxylic acids using our PKS platform in Streptomyces albus. Finally, tuning production of the PKS acyl-CoA substrates enabled production of high titers of specific diols and amino alcohols (1 g/L diol titer in shake flasks), demonstrating high tunability and efficiency of the platform.
2024-12-02 | PXD055149 | Pride
Project description:Branched-chain sugar of pectin
Project description:Postoperative insulin resistance refers to the phenomenon that the body’s glucose uptake stimulated by insulin is reduced due to stress effects such as trauma or the inhibitory effect of insulin on liver glucose output is weakened after surgery.
There is a clear link between postoperative insulin resistance and poor perioperative prognosis. Therefore, exploring interventions to reduce postoperative stress insulin resistance, stabilize postoperative blood glucose, and reduce postoperative complications are clinical problems that need to be solved urgently. In recent years, research on branched-chain amino acids and metabolic diseases has become a hot spot. Studies have found that in the rat model, preoperatively given a high branched-chain amino acid diet can inhibit postoperative insulin resistance and stabilize blood glucose levels. This research plan is to try to add branched-chain amino acids before surgery to observe the occurrence of postoperative insulin resistance in patients.
Project description:Modular polyketide synthases (PKSs) have been proposed as promising megasynthases for retrobiosynthesis because of their fitness for rational carbon skeleton design. However, over the last three decades, all engineered PKSs produce carboxylic acids via terminal thioesterase (TE), which significantly narrows available chemical scope. We proposed the possibility of expanding PKS chemical diversity via terminal thioreductase (TR) engineering, and comprehensively characterised PKS TRs as NADPH-dependent enzymes to terminate polyketides with aldehyde. These aldehyde products can be readily converted to industrially valuable alcohols and amines, demonstrated by an engineered rimocidin PKS-TR producing 1,3-butanediol, 1,3-pentanediol, and 1,3-hexanediol with a total titer of 1008 mg/L in Streptomyces albus, or producing 554 mg/L 1-amino-3-alcohols via post-PKS transamination, both in shake flasks. Furthermore, efficient control of the product profile was achieved by coenzyme A (CoA) substrate regulation, as elevating butyryl-CoA level resulted in 1,3-hexanediol product ratio increased from 11% to 77%. We also demonstrated that PKS-TR can produce biosynthetically challenging branched-chain diols, culminating in production of 166 mg/L branched-chain 2-methyl-1,3-diols via acyltransferase exchange.
Project description:Autism is present in 1% of the population, yet treatments are extremely limited. We identified homozygous inactivating mutations in the BCKDK gene in families presenting with autism and epilepsy. The encoded branched chain ketoacid dehydrogenase kinase protein is responsible for phosphorylation-mediated inactivation of the E1-alpha subunit of branched chain ketoacid dehydrogenase, itself mutated in Maple Syrup Urine Disease (MSUD). Patients with homozygous BCKDK mutations display reductions in BCKDK mRNA and protein, E1-alpha phosphorylation and serum branched chain amino acids (BCAAs). Bckdk knockout mice show abnormal brain amino acids profiles and neurobehavioral defects, which are largely corrected by dietary BCAA supplementation. Thus autism presenting with epilepsy due to BCKDK mutations represent a new and potentially treatable disease.
Project description:Branched-chain aminotransferases (BCAT) are enzymes that initiate the catabolism of branched-chain amino acids (BCAA), such as leucine, thereby providing macromolecule precursors. In order to study the effect of BCAT1 inhibitor (ERG240) on LPS-polarized macrophage transcriptome, we stimulated monocyte derived macrophages (MDMs) with LPS for 8 hours, with or without the presence of ERG240. We then performed whole-genome transcriptome sequencing by RNA-sequencing (RNA-seq).
Project description:We characterised the changes in the inner and outer membrane proteome of Escherichia coli in response to alcohols of different chain lengths. The study provides a fundamental understanding of the key changes in the membrane proteome of E. coli under alcohol stress and reveals a conserved membrane proteomic response of E. coli to a range of alcohols.
2023-10-09 | PXD043021 | Pride
Project description:Metabolic Mechanisms of Higher alcohols in the Fermentation Process of Saccharomyces cerevisiae
Project description:Purpose: The goals of this study are to find out the differential expression genes in the fadR mutant strain(ΔfadR) compared with wild-type (WT) and to further explore the regulation mechanisms of fadR. Methods: Shewanella oneidensis MR-1 WT and ΔfadR were collected in log phage(OD~0.6). RNA extraction was performed using the RNeasy minikit (Qiagen) and the RNA was quantified by using a NanoVue spectrophotometer (GE Healthcare). RNA seq was performed using Illumina NextSeq 500, 2×150 bp. Results: Our study represents that the expression of 146 genes were decreased and 94 genes were increased inΔfadR compared with WT. Branched-chain keto acid dehydrogenase (BKD) produces corresponding branched-chain acyl coenzyme A which further participating branchend-chain fatty acids synthesis. The expression of bkdA2 was also promoted in △fadR compared with WT. Conclusions: Combined with our expression results, it declared that FadR can suppress bkd operon in some degree,which further increase the synthesis of branched-chain fatty acids in ΔfadR.
Project description:This study aims to uncover the effects of cancer-derived branched-chain ketoacids on macrophage polarization and the underlying mechanism. We uncovered the global responses of branched-chain ketoacids-stimulated macrophages by proteomics analysis. Functional enrihment analysis indicated that these ketoacids significantly altered macrophage metabolism, apoptosis and phagocytosis.