Michael Andersen Lomholt

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In this paper, the dynamics of spontaneous shape fluctuations of a single, giant quasi-spherical vesicle formed from a single lipid species is revisited theoretically. A coherent physical theory for the dynamics is developed based on a number of fundamental principles and considerations, and a systematic formulation of the theory is also established. From(More)
Little is known of the selectivity of the blood-brain barrier at birth. Hexoses are transported through the barrier by a facilitating mechanism. To study the capacity of this mechanism to distinguish between analogs of D-glucose, we compared the transport of fluorodeoxyglucose, deoxyglucose, glucose, methylglucose, mannose, galactose, mannitol, and(More)
Fluorescence loss in photobleaching (FLIP) is a widely used imaging technique, which provides information about protein dynamics in various cellular regions. In FLIP, a small cellular region is repeatedly illuminated by an intense laser pulse, while images are taken with reduced laser power with a time lag between the bleaches. Despite its popularity, tools(More)
PACS 05.40.-a – Fluctuation phenomena, random processes, noise, and Brownian motion PACS 87.10.-e – General theory and mathematical aspects PACS 87.16.-b – Subcellular structure and processes PACS 87.18.-h – Biological complexity Abstract –Macromolecular crowding in living biological cells effects subdiffusion of larger bio-molecules such as proteins and(More)
We investigate the translocation of a stiff polymer consisting of M monomers through a nanopore in a membrane, in the presence of binding particles (chaperones) that bind onto the polymer, and partially prevent backsliding of the polymer through the pore. The process is characterized by the rates: k for the polymer to make a diffusive jump through the pore,(More)
We study a Michaelis-Menten reaction for a single two-state enzyme molecule, whose transition rates between the two conformations are modulated by an harmonically oscillating external force. In particular, we obtain a range of optimal driving frequencies for changing the conformation of the enzyme, thereby controlling the enzymatic activity (i.e., product(More)
We present a general and systematic theory of non-equilibrium dynamics of multi-component fluid membranes, in general, and membranes containing transmembrane proteins, in particular. Developed based on a minimal number of principles of statistical physics and designed to be a meso/macroscopic-scale effective description, the theory is formulated in terms of(More)
Recent experiments show that transcription factors (TFs) indeed use the facilitated diffusion mechanism to locate their target sequences on DNA in living bacteria cells: TFs alternate between sliding motion along DNA and relocation events through the cytoplasm. From simulations and theoretical analysis we study the TF-sliding motion for a large section of(More)
UNLABELLED BACKGROUND Cholesterol is an important membrane component, but our knowledge about its transport in cells is sparse. Previous imaging studies using dehydroergosterol (DHE), an intrinsically fluorescent sterol from yeast, have established that vesicular and non-vesicular transport modes contribute to sterol trafficking from the plasma membrane.(More)