A motor protein accelerates from rest with constant acceleration. A protein filament (microtubule) is a hollow tube made of proteins arranged in a helical pattern. Microtubules are one of the main components of the cytoskeleton.
A motor protein accelerates from rest with constant acceleration, an experimentally observed property that has proven difficult to explain by classical theory.
A Motor Protein Accelerates From Rest with Constant Acceleration
A motor protein is a type of molecular motor that uses ATP-driven conformational changes to produce mechanical movement. Motor proteins are integral to many key biological processes, including DNA transcription and translation, protein folding, cell movement and organelle transport.
A motor protein accelerates from rest with constant acceleration until reaching a terminal velocity. The motor then coasts at that velocity for a time, after which it is arrested by an external force. The arrest occurs in a time t_a and the deceleration is abrupt. It sticks to the filament after the arrest so that it does not rebound. (The filament has a low coefficient of friction).
The model of the motor protein is constructed using a spherical bead, a base and two springs.
A motor protein is a protein that converts chemical energy into mechanical action. The motion of the motor protein is studied using the model of the motor protein constructed with a spherical bead, a base and two springs.
The bead moves from rest with constant acceleration in a straight line parallel to its initial position. When the bead reaches the equilibrium position, it reverses its direction and moves back to its original position when it has speed zero again.
The modelled motor protein consists of a spherical bead attached to two spring constants with the bead starting at rest in the centre of the springs.
We consider the problem of a motor protein accelerating from rest with constant acceleration. The modelled motor protein consists of a spherical bead attached to two spring constants with the bead starting at rest in the centre of the springs.
The springs are attached to fixed points which represent a filament. Once the bead has accelerated this results in an imbalance of forces on the springs and the bead will be driven along one of the filaments at a constant velocity. We obtain analytic expressions for both the force and torque balance equations, and solve these equations numerically using MATLAB’s Runge-Kutta solver.
We derive an expression for the acceleration of microtubules based on experimental data for kinesin-1. The numerical solution shows that microtubules can accelerate up to 1.28ms^−2 with kinesin-1 as the motor protein, which is comparable to typical velocities found in biological systems.
The rate of a protein is completely dependent on its environment and the conditions that the protein is facing.
The rate of a protein is completely dependent on its environment and the conditions that the protein is facing. The type of motor protein, the path it has to tread and the conditions of that path all affect its ability to move. Myosins, for example, can only travel along actin filaments in one direction.
They use ATP for energy and take about 10 seconds to walk along an actin filament. Kinesins move along microtubules at about 1 μm per second. Dyneins travel about 0.2 μm per second along microtubules in the opposite direction of kinesins.
The environmental conditions also affect the ability of motor proteins to work correctly. For example, temperature affects dyneins and myosins by decreasing their speed as temperatures increase[2]. However, kinesins are unaffected by temperature variations until they reach very high temperatures near 45 degrees Celsius.
The concentration of ions in the solution where proteins are working also affect them because ion concentration affects how well enzymes such as ATP synthase function. A higher ion concentration means that more ions are available for reactions to occur, which increases the rate at which proteins move.
The protein is placed in a solution and measures the time it takes to move 1 micrometre.
A motor protein is a protein responsible for the movement of cargos inside cells. Motor proteins move along cytoskeletal filaments (actin, myosin, and tubulin).
They use chemical energy converted from ATP hydrolysis to move directionally. The motor domain contains the site that binds and hydrolyzes ATP. In addition the motor domain usually contains a site that binds the track filament.
The protein is placed in a solution and measures the time it takes to move 1 micrometre.
Last Words
The analysis shows that the motor protein is able to accelerate from rest at a constant acceleration. This acceleration is observed because of the intrinsic property of the motor of having positive sensitivity as a result of which the speed increases exponentially over time.
Interestingly, during each acceleration phase only one state variable (the shaft angle) needs to be solved analytically, whereas the variables that are typically difficult to solve (the rotor angles and speed) can be determined numerically without much difficulty.