About

Jun Ohata is an Assistant Professor in the Department of Chemistry at NC State University. He holds a Ph.D. in Chemistry from the University of California, Berkeley, obtained in 2020, a Master's degree from Rice University earned in 2018, and both a Bachelor's degree from Osaka Prefecture University completed in 2011 and 2013. His research focuses on selective chemical reactions on natural proteins, leveraging expertise in organic and organometallic chemistry, protein science, bioconjugation techniques, fluorescence imaging, and biochemical analysis. His group develops chemical tools, particularly protein labeling methods, to study the chemistry of proteins in living systems such as mammalian cells and animal samples. Additionally, his work involves creating functional protein conjugates for material and medicinal applications. His contributions include advancing methods for protein modification, bioconjugation, and chemical sensing, with a particular emphasis on applications in biological systems and health sciences.

Research topics

• Chemistry
• Organic chemistry
• Computational biology
• Biochemistry
• Polymer chemistry
• Combinatorial chemistry
• Stereochemistry
• Biology

Selected publications

• Scalable mechanochemical synthesis of a cyclic dehydroalanine peptide

  Organic & Biomolecular Chemistry · 2026-01-01

  articleOpen accessSenior author

  acyl transfer-based condensation reactions of a diketopiperazine derivative (also known as cyclic glycine dimer or glycine anhydride) through a series of reaction optimization processes to identify scalable conditions. Liquid-assisted mechanochemistry proved important for the promotion of the overall efficiency and reproducibility of the condensation reaction between acetyl-diketopiperazine and paraformaldehyde.

  PublisherOA PDFDOI

• It's a Gas: Bioconjugation With Vapor‐Phase Reagents

  Chemistry - A European Journal · 2026-02-21

  articleOpen accessCorresponding

  Bioconjugation is a large field with many diverse goals, needs, and challenges, that requires a broad toolbox of fundamentally different synthetic approaches. As an emerging class of bioconjugation reagents, gas molecules bring new reactivity and selectivity concepts. Beyond these fundamental questions, gas-phase reagents may have unique advantages, such as access to porous material and structures, and diffusions/penetration differences in reaction in complex tissues or other contexts. This concept article examines vapor-phase reagents, as well as their reactivity and selectivity, for the modification of natural peptides and proteins.

  PublisherOA PDFDOI

• Prebiotic Organic Chemistry of Diketopiperazines

  Asian Journal of Organic Chemistry · 2026-04-01

  articleOpen access1st authorCorresponding

  ABSTRACT Even though the significance of amino acids and polypeptides is well recognized in broad prebiotic chemistry fields, 2,5‐diketopiperazines (DKPs) or cyclic dipeptides remains a mysterious species without clear relevance to the origin of complex biomolecular systems. The aim of this review article is to demonstrate the various roles and functions of DKPs in simulated prebiotic reactions reported over the past few decades. By highlighting both experimental and computational simulations, the formation and reaction of DKP derivatives in a range of prebiotically plausible conditions were discussed from the organic chemistry viewpoint, as the manuscript organization is predicated on fundamental reaction patterns such as photochemical synthesis, aminonitrile chemistry, and amino acid condensation. Analytical challenges of DKPs were identified through the literature review too, as the product detection and characterization are critical not only in prebiotic chemistry but also in synthetic organic chemistry fields. The collection and critical analysis of reports about prebiotically plausible processes of DKPs may imply the breadth of its chemical diversity including the potential relevance to nucleotides, value as a building block to more intricate biomacromolecules, and symmetry breaking.

  PublisherDOI

• Harnessing Cyclohexadiene Chemistry for Chemical Modification of Unprotected Peptides

  The Journal of Organic Chemistry · 2026-05-14

  articleSenior authorCorresponding

  Because of its chemical inertness, phenylalanine is one of the proteinogenic amino acids that does not have many chemical labeling methods for, particularly in unprotected peptide substrates. Inspired by a recently reported mechanochemical Birch reduction method, we tested a reduction-based approach as well as inverse electron-demand Diels-Alder reactions to develop a phenylalanine-targeting bioconjugation method using 1,4-cyclohexadiene as a key chemical species. Chemoselective reduction of the phenyl to cyclohexadienyl group was achieved for dipeptides and tripeptides that do not contain tryptophan residues. Through a computation- and experiment-guided approach, we also demonstrated the possibility of 1,4-cyclohexadiene-based Diels-Alder reactions on an unprotected peptide using a series of monosubstituted tetrazine reagents.

  PublisherDOI

• Prebiotic Organic Chemistry of Diketopiperazines, Cyclic Dipeptides

  ChemRxiv · 2026-02-22

  articleOpen access1st authorCorresponding

  Even though the significance of amino acids and polypeptides is well recognized in broad prebiotic chemistry fields, 2,5-diketopiperazines (DKPs) or cyclic dipeptides remains a mysterious species without clear relevance to the origin of complex biomolecular systems. The aim of this review article is to demonstrate the various roles and functions of DKPs in simulated prebiotic reactions reported over the past few decades. By highlighting both experimental and computational simulations, the formation and reaction of DKP derivatives in a range of prebiotically plausible conditions were discussed from the organic chemistry viewpoint, as the manuscript organization is predicated on fundamental reaction patterns such as photochemical synthesis, aminonitrile chemistry, and amino acid condensation. Analytical challenges of DKPs were identified through the literature review too, as the product detection and characterization are critical not only in prebiotic chemistry but also in synthetic organic chemistry fields. The collection and critical analysis of reports about prebiotically plausible processes of DKPs may imply the breadth of its chemical diversity including the potential relevance to nucleotides, value as a building block to more intricate biomacromolecules, and symmetry breaking.

  PublisherDOI

• Catalytic Serine Labeling in Nonaqueous, Acidic Media

  Chemistry - A European Journal · 2025-01-22 · 4 citations

  articleOpen accessSenior authorCorresponding

  Chemoselective modification of alkyl alcohols (e. g., serine residues) on proteins has been a daunting challenge especially in aqueous media. Herein, we report chemical modification of alkyl alcohols in protein and cell lysate samples using carboxylic acid-based bioconjugation media. The acidic medium is not only useful to suppress reactivity of other nucleophiles in proteins, but the medium also serves as a potentially biomolecule-compatible solvent. The acid-catalyzed acylation strategy has a unique selectivity paradigm compared to the common active-serine-targeted method and would act as a new strategy for studying biological roles of serine residues.

  PublisherOA PDFDOI

• Catalysis in Chemical Modification of Proteins

  ChemCatChem · 2025-04-07 · 6 citations

  articleOpen accessSenior authorCorresponding

  Advancement of catalytic transformations in traditional synthetic organic chemistry have made significant impact on development of novel bioconjugation technologies. While a wide range of applications have become possible through catalytic protein bioconjugation approaches, there has been a lack of literature collectively reviewing advances of chemical modification of proteins through the lens of catalysis. This review article is focused on design principles and chemical strategies of nonenzymatic catalysis for targeting natural protein substrates by identifying seven catalysis patterns as organizing topics: electrocatalysis, photocatalysis, metal catalysis, acid catalysis, organocatalysis, supramolecular catalysis, and heterogeneous catalysis. Many literature examples demonstrated possibility of simple translation of small molecule-based catalysis into protein bioconjugation methodologies, whereas others demonstrated unique approaches such as dual catalytic systems and polypeptide structure-specific catalysis design. With a series of successful examples, the survey of catalytic approaches for protein bioconjugation also highlighted the remaining challenges and potential future directions of the area of catalytic bioconjugation.

  PublisherOA PDFDOI

• InP-Based Quantum Dots as Photosensitizers in Photodynamic Antimicrobial Materials

  ACS Applied Bio Materials · 2025-01-16 · 4 citations

  article

  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 (∼3.2 nm), with light absorption across the entire visible spectrum (λmax ∼550 nm). Under light excitation at 550 nm, the generation of singlet oxygen (1O2) was evidenced by its characteristic phosphorescence signal at 1278 nm, indicating successful energy transfer from the QDs to surface-anchored ACA ligands, in accordance with a type II mechanism for a photodynamically generated singlet oxygen. The InP/ZnSe/ZnS core/shell QDs were applied to cellulose via dip coating, and the resultant QDs-loaded material was assessed for antimicrobial photodynamic inactivation (aPDI) of both Gram-positive [methicillin-resistant Staphylococcus aureus (MRSA; ATCC-44), vancomycin-resistant Enterococcus faecium (VRE; ATCC-2320)] and Gram-negative [multidrug-resistant Acinetobacter baumannii (MDRAB; ATCC-1605), NDM-1 positive Klebsiella pneumoniae (KP; ATCC-2146)] bacteria under illumination (400–700 nm; 85 mW/cm2; 90 min). The highest inactivation was observed for MRSA, achieving at least 99.999% inactivation (5 log units). Antiviral photodynamic inactivation on human coronavirus 229E (HCoV-229E) and feline calicivirus (FCV) demonstrated complete viral inactivation (to the detection limit). Cytotoxicity studies showed that the QDs are nontoxic to mammalian cells in the dark. Together, these results confirm the promising potential of ligand-functionalized InP-based QDs to be employed as nontoxic photosensitizers as materials in self-sterilizing surfaces.

  PublisherDOI

• Tryptophan Bioconjugation through Auxiliary Boron-Accelerated, Additive-Free Friedel–Crafts Alkylation

  JACS Au · 2025-12-19

  articleOpen accessSenior authorCorresponding

  Chemical tools have allowed the interrogation of molecular events in biological systems through the realization of additive-free labeling approaches such as strain-promoted chemistry. Although design and synthesis of strained compounds remain challenging tasks, efforts to identify an alternative chemical strategy to achieve such additive-free labeling are lacking. Serendipitously, we found that a trifluoroborate unit can act as an auxiliary group to enable the additive-free Friedel-Crafts alkylation reaction at room temperature in the potentially protein-compatible solvent hexafluoroisopropanol (HFIP) without any additional catalysts such as a Lewis acidic metal and a Brønsted acid. The structure-reactivity relationship of a set of thiophene electrophiles for the dehydrative alkylation of tryptophan revealed the inability of various functional groups to cause such an additive-free labeling process, while all of the synthesized trifluoroborate variants displayed substantially enhanced reactivity even in the absence of additives. As the boron moiety serving as an auxiliary group remains on the thiophene unit after the tryptophan bioconjugation, facile secondary functionalization of alkylated tryptophan through boron-based chemistry proved to be possible at a protein level. Because strain-promoted chemistry has shown great promise for diverse applications beyond small-molecule studies by eliminating the need for additives/catalysts, the boron auxiliary approach may be a promising chemical strategy in a wide variety of contexts.

  PublisherDOI

• Prebiotic Roles of Formaldehyde as an Activating Agent and a Building Block in Solid-State Peptide Modification

  ACS Bio & Med Chem Au · 2025-09-18 · 1 citations

  articleOpen accessSenior authorCorresponding

  Signal transduction by gaseous small molecules is an essential process in modern living systems, where the gasotransmitters relay cellular signals to bio-(macro)-molecules through covalent bond formation. However, the origin or a primordial version of such signaling events in abiotic worlds has been poorly understood to date. Through examination of chemical reactivities between formaldehyde and cyclic dipeptide/diketopiperazine derivatives in prebiotically relevant solid-state environments, this study demonstrates that the gaseous small molecule may serve not only as a mere building block for the abiotic construction of biomolecules but also as an activating agent that transforms the inert peptide into reactive, prebiotically important chemical species. In addition, superiority of solid-state reactions or mechanochemistry to solution-based reaction conditions described in this article may be an indication of potential significance of the mechanical force-induced chemistry for chemical evolution, in particular for abiotic emergence of polypeptides.

  PublisherDOI

Recent grants

• Chemical labeling strategies using biomolecule-compatible, nonaqueous media

  NIH · $738k · 2024–2029

Frequent coauthors

• Chiamaka Peace Uzoewulu

  88 shared

• Grant N. Shivers

  University of Iowa

  81 shared

• J.-Y Liao

  Hebei University

  81 shared

• S.-J Hu

  City University of Hong Kong

  81 shared

• Ji‐Tai Li

  Guangdong Polytechnic Normal University

  81 shared

• Clinton G. L. Veale

  University of Cape Town

  81 shared

• Soe L. Tun

  University of Iowa

  81 shared

• X.-E Cai

  Nanjing University of Chinese Medicine

  81 shared

Labs

• Ohata GroupPI