Anaerobic microbial acetogenesis is ubiquitous on Earth, and thus plays an important role in the global carbon cycle. The mechanism of carbon fixation in acetogens has attracted great interest from ...various studies for combatting climate change, and even for studying ancient metabolic pathways. Here, we developed a new, simple method for investigating carbon flows in the metabolic reaction of acetogen by conveniently and accurately determining the relative abundance of individual acetate- and/or formate-isotopomers formed in 13C labeling experiments. We measured the underivatized analyte by gas chromatography-mass spectrometry (GC-MS) coupled with a direct aqueous sample injection technique. The individual abundance of analyte isotopomers was calculated by the mass spectrum analysis using the least-squares approach. The validity of the method was demonstrated by determining known mixtures of unlabeled and 13C-labeled analytes. The developed method was applied to study the carbon fixation mechanism of the well-known acetogen Acetobacterium woodii grown on methanol and bicarbonate. We provided a quantitative reaction model for methanol metabolism of A. woodii, which indicated that methanol was not the sole carbon precursor of the acetate methyl group and that 20−22% of the methyl group was formed from CO2. In contrast, the carboxyl group of acetate appeared to form exclusively by CO2 fixation. Thus, our simple method, without laborious analytical procedures, has broad utility for the study of biochemical and chemical processes related to acetogenesis on Earth.
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•A new method for quantifying 13C distribution in acetate and formate was developed.•GC-MS method coupled with the MS spectra analysis using a least-squares approach.•The method was applied to study carbon flow in methanol metabolism of acetogen.•Quantitative reaction model indicated that 20% of acetate methyl was derive from CO2.
Ionizable lipids with branched tails have been used in lipid nanoparticles (LNPs)‐based messenger RNA (mRNA) therapeutics like COVID‐19 vaccines. However, due to the limited commercial availability ...of branched ingredients, a systematic analysis of how the branched tails affect LNP quality has been lacking to date. Herein, α‐branched tail lipids are focused, as they can be synthesized from simple commercially available chemicals, and the length of each chain can be independently controlled. Furthermore, symmetry and total carbon number can be used to describe α‐branched tails, facilitating the design of a systematic lipid library to elucidate “structure–property–function” relationships. Consequently, a lipid library is developed containing 32 different types of α‐branched tails. This library is used to demonstrate that branched chains increase LNP microviscosity and headgroup ionization ability in an acidic environment, which in turn enhances the stability and in vivo efficacy of mRNA‐LNPs. Of the branched lipids, CL4F 8‐6 LNPs carrying Cas9 mRNA and sgRNA could achieve 54% genome editing and 77% protein reduction with a single dose of 2.5 mg kg−1. This mechanism‐based data on branched lipids is expected to provide insights into rational lipid design and effective gene therapy in the future.
Branched‐tail lipids are commonly used for the delivery of messenger RNA (mRNA). However, the exact role of the branched chains remains unclear. To address this, a lipid library is developed containing 32 different types of α‐branched tails. This library enables a systematic comparison and demonstrates that branched chains can enhance the stability, fusogenicity, and functional delivery of mRNA.
An anaerobic thermophilic, rod-shaped bacterium possessing a unique non-lipid sheathed-like structure enveloping a single-membraned cell, designated strain NRmbB1T was isolated from at the deep ...subsurface oil field located in Yamagata Prefecture, Japan. Growth occurred with 40–60°C (optimum, 55°C), 0–2% (2%), NaCl and pH 6.0–8.5 (8.0). Fermentative growth with various sugars was observed. Glucose-grown cells generated acetate, hydrogen, pyruvate and lactate as the main end products. Syntrophic growth occurred with glucose, pyruvate and 3,4,5-trimethoxybenzoate in the presence of an H2-scavenging partner, and growth on 3,4,5-trimethoxybenzoate was only observed under syntrophic condition. The predominant cellular fatty acids were C16:0, iso-C16:0, anteiso-C15:0, and iso-C14:0. Respiratory quinone was not detected. The genomic G+C content was 40.8mol%. Based on 16S rRNA gene phylogeny, strain NRmbB1T belongs to a distinct order-level clade in the class Clostridia of the phylum Firmicutes, sharing low similarity with other isolated organisms (i.e., 87.5% for top hit Moorella thermoacetica DSM 2955T). In total, chemotaxonomic, phylogenetic and genomic characterization revealed that strain NRmbB1T (=KCTC 25035T, =JCM 39120T) represents a novel species of a new genus. In addition, we also propose the associated family and order as Koleobacteraceae fam. nov and Koleobacterales ord. nov., respectively.
Blue nevi are dermal dendritic melanocytic proliferations presenting as papules, nodules or plaques of blue, blue-gray or blue-brown color. Dermoscopic appearance commonly shows global patterns as ...homogeneous mono/dichromatic pigmentation and multichromatic pigmentation. Here, we report the case of a blue nevus with the dermoscopic feature of peripheral streaks with branches. With histopathologic deep sections, we confirmed that dermal dendritic melanocytes were distributed in the direction of the streaks. We emphasize that streaks are a rare but important sign of blue nevi.
Anaerobic microbial acetogenesis is ubiquitous on Earth, and thus plays an important role in the global carbon cycle. The mechanism of carbon fixation in acetogens has attracted great interest from ...various studies for combatting climate change, and even for studying ancient metabolic pathways. Here, we developed a new, simple method for investigating carbon flows in the metabolic reaction of acetogen by conveniently and accurately determining the relative abundance of individual acetate- and/or formate-isotopomers formed in
C labeling experiments. We measured the underivatized analyte by gas chromatography-mass spectrometry (GC-MS) coupled with a direct aqueous sample injection technique. The individual abundance of analyte isotopomers was calculated by the mass spectrum analysis using the least-squares approach. The validity of the method was demonstrated by determining known mixtures of unlabeled and
C-labeled analytes. The developed method was applied to study the carbon fixation mechanism of the well-known acetogen Acetobacterium woodii grown on methanol and bicarbonate. We provided a quantitative reaction model for methanol metabolism of A. woodii, which indicated that methanol was not the sole carbon precursor of the acetate methyl group and that 20-22% of the methyl group was formed from CO
. In contrast, the carboxyl group of acetate appeared to form exclusively by CO
fixation. Thus, our simple method, without laborious analytical procedures, has broad utility for the study of biochemical and chemical processes related to acetogenesis on Earth.
A lasp family protein of Ciona intestinalis Terasaki, Asako G.; Hiruta, Jin; Suzuki, Junko ...
Biochimica et biophysica acta,
2008, 2008-Jan, 2008-1-00, 20080101, Volume:
1779, Issue:
1
Journal Article
Peer reviewed
Lasp-1 and lasp-2 are actin-binding proteins that contain a LIM domain, nebulin repeats, and an SH3 domain and they are significantly conserved in mammalian and avian. Lasp-1 is widely expressed in ...nonmuscle tissues and lasp-2 is specifically expressed in the brain. Genes encoding proteins homologous to lasp-1 and lasp-2 were deposited in the genome/cDNA database of invertebrates such as sea urchins, nematodes, and insects; however, function of their proteins have not been studied in detail.
In this study, we analyzed the gene structure, actin-binding activity, and expression of the lasp protein of the ascidian
Ciona intestinalis (
Ci lasp). A single gene encoding lasp protein was found in the ascidian, and the amino acid sequences of
Ci lasp and other invertebrate lasp proteins exhibited similarity to vertebrate lasp-1 and lasp-2 to the same extent. A part of the exon–intron boundaries was conserved between the vertebrate
lasp-1, the vertebrate
lasp-2 and the invertebrate
lasp genes.
Ci lasp exhibited actin-binding activity in a co-sedimentation assay.
In situ hybridization revealed that the expression of
Ci lasp mRNA was apparent in nervous system of early embryos and was detected in various tissues in young adults. This suggests that the functions of invertebrate lasp proteins might include the functions of vertebrate lasp-1 and lasp-2.
Patients with hematologic malignancies are immunosuppressive and may develop cutaneous or invasive infections as a primary sign of immune suppression. Acute promyelocytic leukemia (acute myeloid ...leukemia M3) is caused by translocation of reciprocal chromosomal rearrangement t(15;17), which produces an oncogenic protein. We herein describe a 71-year-old man having cellulitis with leukocytopenia as a first sign of acute promyelocytic leukemia. Dermatologists and hematologists should keep in mind that patients with a hematologic malignancy, such as acute promyelocytic leukemia, can develop cellulitis with leukocytopenia.
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