Self-reproducing catalyst drives repeated phospholipid synthesis and membrane growth

Hardy, Michael; Yang, Jun; Selimkhanov, Jangir; Cole, Christian M.; Tsimring, Lev S.; Devaraj, Neal K.

doi:10.1073/pnas.1506704112

Cited by 149 publications

(162 citation statements)

References 54 publications

Supporting

Mentioning

150

Contrasting

Unclassified

Order By: Relevance

“…We now added a fifth design principle 25 : 5) use a catalyst to enhance the rate of the final bond forming reaction leading to formation of the assembling molecule. To various degrees, these principles have been applied to controlling self-assembly through enzymatic catalysis 26,27,28,29,30,31 and synthetic catalysis 32,33 . Figure 1.…”

Section: Concept and Motivationmentioning

confidence: 99%

Catalysis of Supramolecular Hydrogelation

et al. 2016

View full text Add to dashboard Cite

CONSPECTUSOne often thinks of catalysts as chemical tools to speed up a reaction, or to have a reaction run under more benign conditions. As such, catalysis has a role to play in the chemical industry and in lab scale synthesis that is not to be underestimated. Still, the role of catalysis in living systems (cells, organisms) is much more extensive, ranging from the formation and breakdown of small molecules and biopolymers, to controlling signal transduction cascades and feedback processes, motility and mechanical action. Such phenomena are only recently starting to receive attention in synthetic materials and chemical systems. 'Smart' soft materials could find many important applications ranging from personalized therapeutics to soft robotics, to name but a few. Until recently, approaches to controlling the properties of such materials were largely dominated by thermodynamics, for instance looking at phase behavior and interaction strength. However, kinetics play a large role in determining the behavior of such soft materials, for instance in the formation of kinetically trapped (metastable) states, or the dynamics of component exchange. As catalysts can change the rate of a chemical reaction, catalysis could be used to control the formation, dynamics and fate of supramolecular structures, when the molecules making up these structures contain chemical bonds whose formation or exchange are susceptible to catalysis. In this Account, we describe our efforts to use synthetic catalysts to control the properties of supramolecular hydrogels. Building on the concept of synthesizing the assembling molecule in the self-assembly medium from non-assembling precursors, we will introduce the use of catalysis to change the kinetics of assembler formation, and thereby the properties of the resulting material. In particular, we will focus on the synthesis of supramolecular hydrogels where the use of a catalyst provides access to gel materials with vastly different appearance and mechanical properties, or controls localized gel formation and the growth of gel objects. As such, catalysis will be applied to create molecular materials that exist outside of chemical equilibrium. In all, using catalysts to control the properties of soft materials constitutes a new avenue for catalysis, far beyond the traditional use in industrial and lab scale synthesis.

show abstract

Section: Concept and Motivationmentioning

confidence: 99%

Catalysis of Supramolecular Hydrogelation

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Reminiscent of natural catalytic processes at the base of many cellular phenomena, (bio-)catalysis can be a valuable tool to control the formation and properties of soft, self-assembled materials. [1][2][3][4] Furthermore, the groups of Rao, Xu and others have recently shown that enzymatic activation of synthetic self-assembling molecules in a cellular environments find promising applications as imaging and therapeutic agents. [5][6][7][8][9][10][11][12][13] A key challenge in this field is the spatial control over self-assembly.…”

Section: Supporting Information Placeholdermentioning

confidence: 99%

Negatively Charged Lipid Membranes Catalyze Supramolecular Hydrogel Formation

et al. 2016

View full text Add to dashboard Cite

In this contribution we show that biological membranes can catalyze the formation of supramolecular hydrogel networks. Negatively charged lipid membranes can generate a local proton gradient, accelerating the acid-catalyzed formation of hydrazone-based supramolecular gelators near the membrane. Synthetic lipid membranes can be used to tune the physical properties of the resulting multicomponent gels as a function of lipid concentration. Moreover, the catalytic activity of lipid membranes and the formation of gel networks around these supramolecular structures are controlled by the charge and phase behavior of the lipid molecules. Finally, we show that the insights obtained from synthetic membranes can be translated to biological membranes, enabling the formation of gel fibers on living HeLa cells.

show abstract

“…Because modern cells are composed of phospholipids, which have been proposed to be transited from protocells composed of fatty acids (16), artificial cells composed of phospholipids should be developed to create a valid model. As an attempt to reconstitute liposomal cell growth, phospholipid synthesis (17)(18)(19)(20) and liposome division (21) have been reported individually but have not been integrated. Temporal liposome reproduction linked with internal DNA replication has been achieved by supplying membrane precursors and birthing daughter liposomes (22).…”

mentioning

confidence: 99%

Sustainable proliferation of liposomes compatible with inner RNA replication

Tsuji

Fujii

Sunami

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Although challenging, the construction of a life-like compartment via a bottom-up approach can increase our understanding of life and protocells. The sustainable replication of genome information and the proliferation of phospholipid vesicles are requisites for reconstituting cell growth. However, although the replication of DNA or RNA has been developed in phospholipid vesicles, the sustainable proliferation of phospholipid vesicles has remained difficult to achieve. Here, we demonstrate the sustainable proliferation of liposomes that replicate RNA within them. Nutrients for RNA replication and membranes for liposome proliferation were combined by using a modified freeze-thaw technique. These liposomes showed fusion and fission compatible with RNA replication and distribution to daughter liposomes. The RNAs in daughter liposomes were repeatedly used as templates in the next RNA replication and were distributed to granddaughter liposomes. Liposome proliferation was achieved by 10 cycles of iterative culture operation. Therefore, we propose the use of culturable liposomes as an advanced protocell model with the implication that the concurrent supplement of both the membrane material and the nutrients of inner reactions might have enabled protocells to grow sustainably.protocell | freeze-thaw | flow cytometry | liposome fusion R econstitution of living cell-like compartments via a bottom-up approach using only well-defined components has remained a challenge in the expansion of our understanding of the possible origin of life, the border between living and nonliving matter, and the use of such compartments in other applications (1-3). Two of the requirements to reconstitute cell growth are the proliferation of compartments (4) and the replication of genetic information (5). These reactions should be sustainable to prevent the extermination of life. Artificial cell models in which phospholipid or fatty acid vesicles encapsulate the replication reactions of genetic information and other biochemical reactions have been proposed (6-10). In addition to replicating RNA/DNA internally, vesicle compartments should grow and divide to proliferate. Fatty acids transform among monomers, small micelles, and enclosed vesicles by changing the pH of the solution (11). The flexibility of fatty acids enables the exchange of fatty acids between vesicles and monomers, reconstituting the model of vesicle "growth" and also "division" into daughter vesicles by shear forces (12, 13). Fatty acid vesicles could continuously grow and divide in a primitive environment, compatible with internal RNA replication (12,14). However, because phospholipids lack flexible dynamics compared with fatty acids, the coupled growth and division of liposomal artificial cells has been difficult to achieve (15). Because modern cells are composed of phospholipids, which have been proposed to be transited from protocells composed of fatty acids (16), artificial cells composed of phospholipids should be developed to create a valid model. As an attempt to reconsti...

show abstract

Self-reproducing catalyst drives repeated phospholipid synthesis and membrane growth

Cited by 149 publications

References 54 publications

Catalysis of Supramolecular Hydrogelation

Catalysis of Supramolecular Hydrogelation

Negatively Charged Lipid Membranes Catalyze Supramolecular Hydrogel Formation

Sustainable proliferation of liposomes compatible with inner RNA replication

Contact Info

Product

Resources

About