Abstract
Fluorescence microscope observation of myofibrils incubated with rhodamine-phalloidin and coumarine-phallacidin showed an initial appearance of fluorescence bands at the Z-lines and near the middle of the sarcomeres indicating preferential binding of dye to actin subunits located at both actin filament ends. After long incubation times (1-3 h) however, a final pattern is reached which consists of fluorescent Z-lines in the center of uniformly labelled actin bands, with greater fluorescence in the Z-lines than in the uniform region outside the Z-lines. Increasing the temperature or the ionic strength increased the rate of change to the final pattern. These data indicate: (1) that the ends of the actin filament are kinetically more accessible to phallotoxins; (2) at long times when equilibrium binding presumably occurs, the concentration of actin subunits in the Z-band is greater than in the rest of the sarcomere.
Original language | English (US) |
---|---|
Pages (from-to) | 594-597 |
Number of pages | 4 |
Journal | Journal of Muscle Research and Cell Motility |
Volume | 14 |
Issue number | 6 |
DOIs | |
State | Published - Dec 1993 |
Externally published | Yes |
ASJC Scopus subject areas
- Biochemistry
- Physiology
- Cell Biology