Publications by authors named "J Ohata"

Chemoselective modification of alkylalcohols (e.g., serine residues) on proteins has been a daunting challenge especially in aqueous media.

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Ligand-functionalized InP-based quantum dots (QDs) have been developed as an innovative class of nontoxic photosensitizer suitable for antimicrobial applications, aimed at reducing or preventing pathogen transmission from one host to another via high contact surfaces. A hot injection method followed by functionalization via ligand exchange with 9-anthracene carboxylic acid (ACA) yielded the desired core/shell InP/ZnSe/ZnS QDs. Transmission electron microscopy (TEM) revealed these QDs to be uniform in size (∼3.

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Copper is an essential nutrient for sustaining vital cellular processes spanning respiration, metabolism, and proliferation. However, loss of copper homeostasis, particularly misregulation of loosely bound copper ions which are defined as the labile copper pool, occurs in major diseases such as cancer, where tumor growth and metastasis have a heightened requirement for this metal. To help decipher the role of copper in the etiology of cancer, we report a histochemical activity-based sensing approach that enables systematic, high-throughput profiling of labile copper status across many cell lines in parallel.

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While their broad utility in various chemistry fields were well recognized for decades, fluoroalcohols have recently emerged as a unique solvent system for bioconjugation development. This review describes examples and roles of fluoroalcohols such as trifluoroethanol (TFE) and hexafluoroisopropanol (HFIP) for chemical modification of biomolecules such as polypeptides, nucleic acids, and saccharides. Many chemical modification processes were facilitated by notable functions of those fluoroalcohols such as a proton shuttle, reversible adduct formation with reactive species, and compatibility with electrochemistry/photochemistry.

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Despite the unmet needs for chemical tools to study biological roles of tryptophan in living systems, there has been a lack of chemical modification methods for tryptophan residues that can be used in cellular environments. Driven by a preliminary computational study of our previous research, this work experimentally examined our hypotheses to translate the metal-catalyzed tryptophan modification method in hexafluoroisopropanol (HFIP) into a metal-free process. While one of the hypotheses merely confirmed the superiority of the thiophene-ethanol reagent developed in the previous report, the second hypothesis resulted in the identification of a trifluoroborate salt and an acidic ionic liquid as alternatives for the catalysis.

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