Hashim P.K

Hokkaido University | Hokudai

The conceptual expansion of template polymerization within the realm of size-controlled drug delivery systems is examined, with a particular emphasis on its application in RNA delivery.

Photoswitches are molecules that can absorb light of specific wavelengths and undergo a reversible transformation between their trans and cis isomeric forms. In phenylazo photoswitches, it is common for the less stable cis (Z) isomer to convert back to the more stable trans (E) isomer either through photochemical or thermal means. In this research,...

We serendipitously found that chaperonin GroEL can hydrolyze ortho-nitrophenyl β-galactoside (ONPG), a well-known substrate of β-galactosidase enzyme. The ONPG hydrolysis by GroEL follows typical enzyme kinetics. Our experiments and molecular...

Herein, we report an ATP‐responsive nanoparticle (GroELNP) whose surface is fully covered with the biomolecular machine “chaperonin protein GroEL”. GroELNP was synthesized by DNA hybridization between a gold NP with DNA strands on its surface and GroEL carrying complementary DNA strands at its apical domains. The unique structure of GroELNP was vis...

Herein, we report an ATP‐responsive nanoparticle ( GroEL NP) whose surface is fully covered with the biomolecular machine “chaperonin protein GroEL”. GroEL NP was synthesized by DNA hybridization between a gold NP with DNA strands on its surface and GroEL carrying complementary DNA strands at its apical domains. The unique structure of GroEL NP was...

A novel class of photoswitches based on a phenylazothiazole scaffold that undergoes reversible isomerization under visible-light irradiation is reported. The photoswitch, which comprises a thiazole heteroaryl segment directly connected to a phenyl azo chromophore, has very different spectral characteristics, such as a redshifted absorption maximum...

Adenosine triphosphate (ATP) is the energy source for various biochemical processes and biomolecular motors in living things. Development of ATP antagonists and their stimuli‐controlled actions offer a novel approach to regulate biological processes. Herein, we developed azobenzene‐based photoswitchable ATP antagonists for controlling the activity...

The research field of supramolecular polymerization has dramatically progressed in the last three decades, and much deeper insights into its new mechanisms, including kinetic and thermodynamic aspects, have become available. Furthermore, a much wider variety of noncovalent interactions have been exploited for connecting monomers, and the importance...

The introduction of asymmetry into molecular systems by external chiral stimuli greatly contributes to our understanding of the intriguing homochirality which exists in biomolecules. Circularly polarized light (CPL) is a well‐known chiral physical force (right‐ or left‐handed), which can influence the enantiomeric equilibrium of racemic chiral comp...

Transferrin (Tf) is known to induce transcytosis, which is a consecutive endocytosis/exocytosis event. We developed a Tf-appended nanocaplet (TfNC⊃siRNA) for the purpose of realizing siRNA delivery into deep tissues and RNA interference (RNAi) subsequently. For obtaining TfNC⊃siRNA, a macromonomer (AzGu) bearing multiple guanidinium ion (Gu⁺) units...

Molecular adhesion based on multivalent interactions plays essential roles in various biological processes. Hence, “molecular glues” that can adhere to biomolecules may modulate biomolecular functions and therefore can be applied to therapeutics. This tutorial review describes design strategies for developing adhesive motifs for biomolecules based...

A series of water-soluble telechelic dithiol monomers bearing multiple guanidinium ion (Gu(+)) units in their main chains (Figure 1) were synthesized for packaging siRNA by template-assisted oxidative polymerization at their thiol termini. In the presence of siRNA, oxidative polymerization of (TEG)Gu4 affords a uniform-sized (7 ± 2 nm) nanocaplet c...

The ability to photoinduce enantiomeric excess from the chirality of circularly polarized light (CPL) is pertinent to the study of the origin of homochirality in biomolecules. Such CPL-induced reactions, including both chirality generation and formation of partial enantiomeric imbalance, from nonchiral starting compounds have been known, however, o...

Ein Asymmetriezentrum und die entsprechenden trennbaren Enantiomere werden durch E/Z-Photoisomerisierung in einem Azobenzol-basierten prochiralen Molekül erzeugt. Das Asymmetriezentrum entsteht durch lichtinduzierte Änderungen an den Substituenten des Zentralatoms, und thermische Z/E-Isomerisierung regeneriert die ursprüngliche Molekülsymmetrie. Di...

New phototriggered molecular machines based on cyclic azobenzene were synthesized in which a 2,5-dimethoxy, 2,5-dimethyl, 2,5-difluorine or unsubstituted-1,4-dioxybenzene rotating unit and a photoisomerizable 3,3'-dioxyazobenzene moiety are bridged together by fixed bismethylene spacers. Depending upon substitution on the benzene moiety and on the...