A Mathematical Model Predicting Gliding Speed of Actin Molecular Shuttles Over Myosin Motors in the Presence of Defective Motors

Motor proteins are molecular machines that operate in living cells. These motor proteins have been used in vitro for applications such as nano- and microscale devices as transport systems in biosensors, biocomputing, and molecular communication. By introducing motor proteins into these devices, motor proteins become defective due to unfavorable binding to device surfaces, causing a decrease in transport speed or malfunctioning of transport. However, systematic experimental investigations of the effects of defective motors are hampered by difficulties in controlling the number of defective motors on surfaces. Here, we show a systematic study on the effects of defective motors on the motility of transport by using a mathematical model. The model predicted that motility is independent of the length of the associated filaments and depends on the ratio of the active motors. The model revealed that the ratio of active motors of more than 80% is required for sustainable motility. This insight would be useful in choosing appropriate materials for devices integrated with motor proteins.