Self‐assembly of biological molecules and structures is a fundamental property of life. Whereas most biological functions are based on self‐assembled proteins and protein complexes, the self‐assembly ...of lipids is important for the spatial organization of heterogeneous cellular reaction environments and to catalyze cooperative interactions on/with membranes. Lipid domains or “rafts”, which are known to selectively recruit proteins, play an important functional role in sorting and trafficking of membrane components between subcellular organelles. However, how the recruitment and interactions of proteins in turn contributes to the formation and turnover of these structures has not been systematically addressed, due to the large variety in membrane–protein features and their spatiotemporal dynamics. The small size and transient nature of lipid domains adds to the complexity in visualizing them in living cells. Here, DNA origami is presented as a programmable tool to mimic protein clustering and assembly on membranes and illustrate how nanometer sized lipid domains coalesce into visible domains upon origami self‐assembly in defined patterns. Hence, the local membrane composition can be efficiently regulated by the self‐assembly of peripheral membrane binders. This reinforces the hypothesis that lipid rafts in cells occur as a result of membrane–protein interactions and, in particular, protein self‐assembly.
Self‐assembly of both lipids and anchored DNA origami is codependent on each other. Lipid domains coalesce with the cross‐linking of DNA origami following their preference for lipid domains at specific salt conditions. As a result, lipid domains can be patterned by bound DNA origami on the membrane.
Membranes are the key structures to separate and spatially organize cellular systems. Their rich dynamics and transformations during the cell cycle are orchestrated by specific membrane‐targeted ...molecular machineries, many of which operate through energy dissipation. Likewise, man‐made light‐activated molecular rotary motors have previously shown drastic effects on cellular systems, but their physical roles on and within lipid membranes remain largely unexplored. Here, the impact of rotary motors on well‐defined biological membranes is systematically investigated. Notably, dramatic mechanical transformations are observed in these systems upon motor irradiation, indicative of motor‐induced membrane expansion. The influence of several factors on this phenomenon is systematically explored, such as motor concentration and membrane composition., Membrane fluidity is found to play a crucial role in motor‐induced deformations, while only minor contributions from local heating and singlet oxygen generation are observed. Most remarkably, the membrane area expansion under the influence of the motors continues as long as irradiation is maintained, and the system stays out‐of‐equilibrium. Overall, this research contributes to a comprehensive understanding of molecular motors interacting with biological membranes, elucidating the multifaceted factors that govern membrane responses and shape transitions in the presence of these remarkable molecular machines, thereby supporting their future applications in chemical biology.
Explore the nuanced relationship between light‐driven molecular motors and lipid membranes in this research. Delve into the continuous interplay, observing how these motors, akin to dynamic springs fueled by light, orchestrate subtle yet fascinating shape transitions in membranes. Observe how these out‐of‐equilibrium systems can modulate area expansion through their action in lipid membranes.
Nanotechnology often exploits DNA origami nanostructures assembled into even larger superstructures up to micrometer sizes with nanometer shape precision. However, large-scale assembly of such ...structures is very time-consuming. Here, we investigated the efficiency of superstructure assembly on surfaces using indirect cross-linking through low-complexity connector strands binding staple strand extensions, instead of connector strands binding to scaffold loops. Using single-molecule imaging techniques, including fluorescence microscopy and atomic force microscopy, we show that low sequence complexity connector strands allow formation of DNA origami superstructures on lipid membranes, with an order-of-magnitude enhancement in the assembly speed of superstructures. A number of effects, including suppression of DNA hairpin formation, high local effective binding site concentration, and multivalency are proposed to contribute to the acceleration. Thus, the use of low-complexity sequences for DNA origami higher-order assembly offers a very simple but efficient way of improving throughput in DNA origami design.
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