Physicists Develop Strategies for Microtransporters to Optimize Movement in Biological Cells

Conditions can get rough in the micro- and nanoworld. For example, to ensure that nutrients can still be optimally transported within cells, the minuscule transporters involved need to respond to the fluctuating environment. Physicists at Heinrich Heine University Düsseldorf (HHU) and Tel Aviv University in Israel have used model calculations to examine how this can succeed. They have nowpublishedtheir results—which could also be relevant for future microscopic machines—in the journalNature Communications. When planning an ocean crossing, sailors seek a course that makes optimum use of favorable wind and ocean currents, and maneuver in order to save time and energy. They also react to random fluctuations in wind and currents, and take advantage of fair winds and waves. Such considerations with regard to energy costs are also important for transport processes at the micro- and nanoscale. For example, molecular motors should use as little energy as possible when transporting nutrients from A to B between and within biological cells. However, the conditions are much rougher in the highly dynamic environment of a living organism and the fluctuations to which the microtransporters need to respond are significantly larger. Large deterministic forces such as the periodicity of the heartbeat can however be harvested to realize optimum movement strategies; particles can surf on the waves of the microcosm, so to speak. A German-Israeli team of physicists headed by Professor Dr. Hartmut Löwen from the Institute for Theoretical Physics II at HHU and Professor Dr. Yael Roichman from Tel Aviv University have now examined how to minimize the amount of work required to guide a particle to a specified destination within a specified time in a microscopic environment.