Muscles are biological systems with a hierarchical organization. The image below demonstrates that a single muscle (highest level) is made up of many fibers (second highest level) which are further separated into contractile units called sarcomeres (third highest level). Sarcomeres consist of protein filaments (orange and pink structures in the sarcomere image) that have myosins (green motor proteins in image).
These myosins utilize molecular energy and cyclically attach and detach to filaments, exerting force and displacing a filament a small amount during each cycle. The coordinated actions of over a quadrillion myosin proteins are responsible for one muscular contraction.
Because these are mechanically based biological phenomena, traditional bio-chemical approaches are insufficient for describing the system, but our mechanical engineering approach elucidates many aspects of the system that were not previously explainable.
Myosins are often referred to as nano-machines, and vastly outperform any synthetic nano-machine that engineers are currently able to produce. Myosins are highly efficient and robust in the body, and these characteristics have motivated engineers to utilize myosins directly in a number of nano-technologies. Natural myosins have many functions within cells besides muscle contraction, and have slightly different structures to accomplish these tasks with varying performance levels.
Our goal is to control and design synthetic myosins by altering their structures in order to produce a desired performance. The design of synthetic myosin has additional applications in bio-medical fields, such as creating synthetic muscle or curing muscle diseases. Below is a video demonstrating the force a myosin produces as it cycles.
Because myosins work in large groups to create muscle contractions, it is not sufficient to simply model one myosin. We produced a methodology for designing and simulating a large number of myosins as demonstrated in the video below.
Using the simulation software described above, we conducted a virtual experiment by varying three myosin design parameters and comparing the results to a datum myosin design. The results below demonstrate the differences in performance that arise from different synthetic myosin designs, and are the first steps in building a design methodology for producing synthetic myosins that are optimized for a number of applications.
This webpage presents a simplified view of muscle physiology and myosin analysis. In order to learn more, there are a number of physiology textbooks and journal articles which are focused specifically on the nano- macro- connection between myosins and muscle. Work on this page is currently in the publication process, and the resulting journal articles will be linked as they are released.