Muneyuki Matsuo

The hypothesis that prebiotic molecules were transformed into polymers that evolved into proliferating molecular assemblages and eventually a primitive cell was first proposed about 100 years ago. To the best of our knowledge, however, no model of a proliferating prebiotic system has yet been realised because different conditions are required for polymer generation and self-assembly. In this study, we identify conditions suitable for concurrent peptide generation and self-assembly, and we show h

DNA is an essential carrier of sequence-based genetic information for all life today. However, the chemical and physical properties of DNA may also affect the structure and dynamics of a vesicle-based model protocell in which it is encapsulated. To test these effects, we constructed a polyethylene glycol-grafted giant vesicle system capable of undergoing growth and division. The system incorporates a specific interaction between DNA and lipophilic catalysts as well as components of PCR. We found

As a supramolecular micromachine with information flow, a giant vesicle (GV)-based artificial cell that exhibits a linked proliferation between GV reproduction and internal DNA amplification has been explored in this study. The linked proliferation is controlled by a complex consisting of GV membrane-intruded DNA with acidic amphiphilic catalysts, working overall as a lipo-deoxyribozyme. Here, we investigated how a GV-based artificial cell containing this lipo-deoxyribozyme responds to diverse e

Subsequent synthesis and detection using droplets as microreactors have shown promise in the development of novel materials and drugs because microreactors enable small-scale synthesis and detection of covalent/non-covalent intermolecular interactions. Self-organization exhibited by autonomous droplets under non-equilibrium conditions is beneficial for manipulating the sequentiality and selectivity of droplet coalescence because expensive equipment or elaborate techniques are not required with t

An organic droplet containing thymol acetate (TA) floating on a sodium dodecyl sulfate aqueous phase was examined to develop a novel self-propelled object based on reaction kinetics. Two types of oscillatory motion, without back-and-forth motion (Osc I) and with back-and-forth motion (Osc II), were observed by varying the pH of the aqueous phase. The oscillation frequency reached its maximum at pH 9.6, coinciding with the occurrence of Osc II. The kinetics of the hydrolysis of TA as a reactant a

In this review, we discuss various methods of reproducing life dynamics using a constructive approach. An increase in the structural complexity of a model protocell is accompanied by an increase in the stage of reproduction of a compartment (giant vesicle; GV) from simple reproduction to linked reproduction with the replication of information molecules (DNA), and eventually to recursive proliferation of a model protocell. An encounter between a plural protic catalyst (<b>C</b>) and DNA within a

Two novel amphiphiles, <i>N</i>-(3-nitrophenyl)stearamide (MANA) and <i>N</i>,<i>N'</i>-(4-nitro-1,3-phenylene)distearamide (OPANA), were synthesized by reacting nitroanilines with one or two equivalents of stearic acid. We investigated how the molecular structures of these compounds influenced the characteristics of a self-propelled camphor disk placed on a monolayer of the synthesized amphiphiles. Three types of motion were observed at different surface pressures (<i>Π</i>): continuous motion

Oscillatory self-propulsion can be achieved under nonequilibrium conditions. In the case of a camphor boat, the periods of oscillatory motion were determined by the lateral (two-dimensional) transport length of camphor molecules at the solid plastic/water interface. However, the control of self-propulsion by different mass transport paths has not yet been explored. We observed new fluidic behaviors in the oscillatory motion of self-propelled objects. The period of oscillatory motion was determin

The Belousov–Zhabotinsky (BZ) reaction was investigated to understand how the direction of traveling waves (TWs) is determined in a spherical field. A cation-exchange resin bead loaded with the catalyst of the BZ reaction was placed on a glass plate coated with silicone greases with different surface densities. TWs were generated at the contact point between the bead and glass plate for a lower density silicone grease, and at the upper half of the bead for a higher density silicone grease. In ad

A self-propelled sodium oleate (OleNa) disk was investigated at an oil/aqueous interface prepared in an annular channel to induce characteristic features of self-propulsion. When the pH of the aqueous phase was changed, three types of motion were observed, i.e., unidirectional motion at 3.0 ≤ pH ≤ 6.0, motion with inversion at 8.0 ≤ pH ≤ 9.0, and no motion at 11.0 ≤ pH ≤ 12.0. At pH = 8.0, the interfacial tension and complementary contact angle of the meniscus oscillated simultaneously. The mech

Self-propulsion of a thymol acetate (TA) droplet on a sodium dodecyl sulfate (SDS) aqueous solution buffered at pH 9, which was driven by thymol (TOH) produced from TA, was investigated as a function of the concentration of SDS (<i>C</i>_SDS) to elucidate its control effect. The TA droplet exhibited three types of back-and-forth motion depending on <i>C</i>_SDS, i.e., partial back-and-forth motion with oscillatory motion and full back-and-forth motion with either oscillatory