Purification and characterization of myosin from wheat mitochondria

Myosin was purified from wheat mitochondria using DE-52 anion exchange chromatography and Sephacryl S-300 gel filtration. The molecular weight of its heavy chain is about 210 ku, similar to that of muscle myosin II (205 ku), and it could be recognized by the polyclonal antibodies against human skeletal muscle myosin II. The ATPase activity of the mitochondrial myosin stimulated by F-actin from chicken muscle is 202.5 nmoles Pi/min · mg. The mitochondrial myosin could be activated by Ca²⁺ and was not inhibited by Ca²⁺ at high concentration. The results demonstrate that the myosin of wheat mitochondria shares some similarities with the skeletal muscle myosin II.