Myosin isolated from baby hamster kidney cells consists of heavy and light chains, exhibits ATPase activity stimulated 2-fold by skeletal actin, and forms bipolar thick filaments.
The study characterizes the biochemical and immunological properties of myosin isolated from baby hamster kidney cells, demonstrating its structural composition and localization in stress fibres.
ABSTRACT Myosin has been isolated from baby hamster kidney cells (BHK21/C13) in high yield and characterized biochemically and immunologically. The subunit composition consists of 2 heavy chains, approximately 2ooo∞ Daltons each, and 2 classes of light chains of approximately 16 000 and 20000 Daltons. The myosin exhibits ATPase activity in the presence of K+-EDTA or Ca2+ but very little activity with Mg2+-ATP. The Mg2+-ATPase activity is stimulated only about 2-f0ld by skeletal actin, but a much larger activation is obtained in the presence of a protein kinase isolated from chicken gizzard. The increase in actin activation is accompanied by the phosphorylation of the 20000-Dalt0n light chain. BHK21 myosin is insoluble at low ionic strength and forms typical bipolar thick filaments. A specific antiserum generated against this protein forms a single precipitin line with the antigen but does not crossreact with either skeletal or smooth muscle myosin. The antiserum also specifically stains stress fibres in BHK21 cells as shown by indirect immunofluorescence.
Yerna et al. (Thu,) reported a other. Myosin isolated from baby hamster kidney cells consists of heavy and light chains, exhibits ATPase activity stimulated 2-fold by skeletal actin, and forms bipolar thick filaments.