Publications by authors named "Keiko Momma"

Patients with peach allergy who experience severe symptoms, including anaphylaxis, reportedly have a higher positivity for peach gibberellin-regulated protein (GRP)-specific immunoglobulin (Ig) E than those with only oral symptoms. However, a study in Italy investigating apple allergy (another Rosaceae fruit) found no clear association between apple GRP-specific IgE levels and clinical disease types. This study aimed to evaluate the clinical utility of GRP-specific IgE measurement in Japanese patients with apple allergy.

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Bacteriophage T4 gene 32 protein (gp32) preferentially binds to single-stranded DNA (ssDNA) to facilitate DNA replication but shows weak binding to double-stranded DNA (dsDNA). Polyclonal and monoclonal antibodies against gp32 were raised, and an enzyme-linked immunosorbent assay was used to evaluate their reactivities against gp32. The reactivity of the monoclonal antibody MGP45 was diminished in the presence of 5 ng/mL dsDNA, suggesting a conformational change that reduces epitope availability.

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Collagens are abundant structural proteins found in both mammalian and marine species, and attractive biomaterials used in various fields. Jellyfish collagen-based products have become increasingly popular because of their clinically proven health benefits such as the effects of skin wound healing and immune stimulation. To develop detection tools for jellyfish collagen, we generated four monoclonal antibodies, MCOL1, 2, 3, and 4, by immunizing mice with moon jellyfish collagen.

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Article Synopsis
  • * To detect NIV in grains, scientists developed an immunoassay by first creating NIV and then generating specific antibodies against it using a unique process involving linker and glutaric anhydride.
  • * The study successfully produced two monoclonal antibodies that effectively identify NIV in a competitive enzyme-linked immunosorbent assay, demonstrating their specificity by not reacting with other similar toxins.
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Melanocortin-4 receptor (MC4R) is a critical regulator of appetite and energy expenditure in rodents and humans. MC4R deficiency causes hyperphagia, reduced energy expenditure, and impaired glucose metabolism. Ligand binding to MC4R activates adenylyl cyclase, resulting in increased levels of intracellular cyclic adenosine monophosphate (cAMP), a secondary messenger that regulates several cellular processes.

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Gibberellin-regulated protein (GRP) is a fruit severe allergen. The amounts of GRP expression normalized against actin in peach were determined by reverse transcription-quantitative PCR (RT-qPCR). The results were consistent with those determined by enzyme-linked immunosorbent assay (ELISA).

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In this study, monoclonal antibodies against two major fruit allergens-gibberellin-regulated protein (GRP) and lipid transfer protein (LTP)-were established. Sandwich enzyme-linked immunosorbent assays (ELISAs) for the quantification of peach GRP and LTP were constructed using these antibodies. Both ELISAs reacted with the respective antigens when heated at 100ºC for 20 min, but not when reduced with sodium sulfite, indicating that GRP and LTP are heat-stable, while disulfide bonds play an important role in their native steric structures.

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Article Synopsis
  • - The Rosaceae family includes various fruits like peach, apple, and strawberry, with specific allergens such as Bet v 1, profilin, and lipid transfer proteins (LTP) causing oral and generalized allergic reactions.
  • - A case study of a 15-year-old boy revealed he had generalized allergic symptoms triggered by strawberry when coupled with exercise, confirmed through an oral food challenge test.
  • - The study highlights strawberry GRP as a potential allergenic component responsible for exercise-induced symptoms in this case, marking the first investigation into this relationship and indicating a need for further research on strawberry allergies.
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The melanocortin 4 receptor (MC4R) plays an important role in the regulation of appetite and energy expenditure in humans and rodents. Impairment of MC4R signaling causes severe obesity. MC4R mainly couples to the G-protein G.

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Background: Pollen-food allergy syndrome (PFAS) usually manifests as an itching sensation in the mouth and throat immediately after eating fresh fruits and vegetables. However, some patients with PFAS experience systemic symptoms including anaphylaxis. In Europe, cypress gibberellin-regulated protein (GRP) has been noted to cause allergenicity and exhibit cross-reactivity with peach GRP.

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Recent findings indicate that mRNA splicing inhibitors can be potential anticancer candidates. We have previously established a screening system which monitors mRNA processing in order to identify mRNA processing inhibitors. Among a number of dietary resources, isoflavone fractions showed an inhibitory effect of mRNA processing.

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Sphingomonas sp. strain A1, a Gram-negative bacterium, directly incorporates alginate polysaccharide into the cytoplasm through a periplasmic alginate-binding protein-dependent ATP-binding cassette transporter. The polysaccharide is degraded to monosaccharides via the formation of oligosaccharides by endo- and exotype alginate lyases.

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A number of proteins complete mRNA processing in the nucleus, thus, inhibitor of mRNA processing is worth finding to analyze the mechanism of mRNA maturation in detail. Here, we established a monitoring system for mRNA processing using a test compound, spliceostatin A (SSA), which inhibits mRNA splicing. This system should serve to facilitate the discovery of novel compounds from natural resources that inhibit mRNA processing.

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Article Synopsis
  • * The C-terminal domain of FlgJ (SPH1045-C), from Sphingomonas sp. strain A1, was expressed in E. coli, purified, and shown to be most effective at lysing bacteria at pH 6.0 and 37°C.
  • * The X-ray crystallography revealed that SPH1045-C has a unique structure with two lobes and a cleft that likely serves as the active site; while it shares similarities with other lysozymes, its
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Article Synopsis
  • A methanol extract from Alsomitra macrocarpa leaves and branches caused noticeable changes in the shape of human stellate cells (LX-2) and similar effects were seen in other cell types.
  • The main active compound purified from the extract was identified as cucurbitacin E (Cuc E), which is known to disrupt the actin cytoskeleton.
  • Using fluorescence assays, the study demonstrated that Cuc E directly interacts with actin, resulting in stabilization of polymerized actin and leading to noticeable aggregation in cells treated with Cuc E.
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Sphingomonas sp. A1 possesses specialized membrane structures termed 'superchannels' that enable the direct incorporation of macromolecules into the cell. We have engineered two related sphingomonads, the dioxin-degrading S.

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Cells of Sphingomonas sp. A1 directly incorporate a macromolecule, alginate, into the cytoplasm through a biosystem, super-channel, consisting of a pit on the cell surface, alginate-binding proteins in the periplasm, and an ATP-binding cassette transporter in the inner membrane. The alginate is finally depolymerized into constituent monosaccharides by polysaccharide lyases present in the cytoplasm.

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NAD kinase from Mycobacterium tuberculosis (Ppnk) uses ATP or inorganic polyphosphate [poly(P)]. Ppnk overexpressed in Escherichia coli was purified and crystallized in the presence of NAD. Preliminary X-ray analysis of the resultant crystal indicate that the crystal belongs to hexagonal space group P6(2)22 and is holo-Ppnk complexed with NAD.

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Generally, when microbes assimilate macromolecules, they incorporate low-molecular-weight products derived from macromolecules through the actions of extracellular degrading enzymes. However, a Gram-negative bacterium, Sphingomonas sp. A1, has a smart biosystem for the import and depolymerization of macromolecules.

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A Gram-negative bacterium, Sphingomonas sp. A1, has a macromolecule (alginate) import system consisting of a pit on the cell surface and an alginate-specific ATP-binding cassette importer in the inner membrane. Transport of alginate from the pit to the ABC importer is probably mediated by two periplasmic binding protein homologues (AlgQ1 and AlgQ2).

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NAD kinase is a key enzyme in NADP biosynthesis. We solved the crystal structure of polyphosphate/ATP-NAD kinase from Mycobacterium tuberculosis (Ppnk) complexed with NAD (Ppnk-NAD) at 2.6A resolution using apo-Ppnk structure solved in this work, and revealed the details of the structure and NAD-binding site.

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Sphingomonas sp. A1 possesses a high molecular weight (HMW) alginate uptake system composed of a novel pit formed on the cell surface and a pit-dependent ATP-binding cassette (ABC) transporter in the inner membrane. The transportation of HMW alginate from the pit to the ABC transporter is mediated by the periplasmic HMW alginate-binding proteins AlgQ1 and AlgQ2.

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