Myosin VI is a molecular motor involved in intracellular vesicle and organelle transport. To carry out its cellular functions myosin VI moves toward the pointed end of actin, backward in relation to all other characterized myosins. Myosin V, a motor that moves toward the barbed end of actin, is processive, undergoing multiple catalytic cycles and mechanical advances before it releases from acti...

Due to a unique addition to the lever arm-positioning region (converter), class VI myosins move in the opposite direction (toward the minus-end of actin filaments) compared to other characterized myosin classes. However, the large size of the myosin VI lever arm swing (powerstroke) cannot be explained by our current view of the structural transitions that occur within the myosin motor. We have ...

THE JOURNAL OF BONE AND JOINT SURGERY e analysed one surgeon’s attempt to reconstruct the hip in 66 patients (84 hips) with chronic dislocation and to restore the height of the centre of rotation above the transverse teardrop line, the bodyweight lever arm, the abductor lever arm, and the abductor angle to normal. The outcome was assessed using a patient profile at 0, 10 and 20 years, a clinica...

The processive motor myosin V has a relatively high affinity for actin in the presence of ATP and, thus, offers the unique opportunity to visualize some of the weaker, hitherto inaccessible, actin bound states of the ATPase cycle. Here, electron cryomicroscopy together with computer-based docking of crystal structures into three-dimensional (3D) reconstructions provide the atomic models of myos...

Two recent articles addressed the power-stroke of myosin VI molecules during stepping. Although both groups measured the angles of fluorescent probes attached on the myosin VI molecule lever arm using polarized fluorescence techniques, they differ about whether the myosin VI lever arm rotation is fixed or variable. Here we discuss the causes of the discrepancy between the two studies and the im...

An improved version of the " optical bar " intracavity readout scheme for gravitational-wave antennae is considered. We propose to call this scheme " optical lever " because it can provide significant gain in the signal displacement of the local mirror similar to the gain which can be obtained using ordinary mechanical lever with unequal arms. In this scheme displacement of the local mirror can...

This study presents a photo-driven micro-lever fabricated to multiply optical forces using the two-photon polymerization 3D-microfabrication technique. The micro-lever is a second class lever comprising an optical trapping sphere, a beam, and a pivot. A micro-spring is placed between the short and long arms to characterize the induced force. This design enables precise manipulation of the micro...

The myosins are a large family of actin-binding motor proteins that convert stored chemical energy into work, with important functions in intracellular transport, force generation, and mechanosensation (1). Despite many advances in understanding the mechanical and kinetic properties of purified myosins in vitro, the signals that regulate the functions of these molecular motors in cells are not ...

The paper discusses the problem of a machine being “sensed” by its operator. It is shown that reducing the operator’s loading with work necessary for controlling – caused by a wide use of servomechanisms – can result in deterioration of the quality of work of the human-machine system. To study this quality, the quality of regulation criterion used in automatic control engineering was chosen. It...

Conformational transitions in macromolecular complexes often involve the reorientation of leverlike structures. Using a simple theoretical model, we show that the rate of such transitions is drastically enhanced if the lever is bendable, e.g., at a localized hinge. Surprisingly, the transition is fastest with an intermediate flexibility of the hinge. In this intermediate regime, the transition ...