ISSN:
1573-2657
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Although chicken myosin S1 has recently been crystallized and its structure analysed, the relaxed periodic arrangement of myosin heads on the chicken thick filament has not been determined. We report here that the cross-bridge array of chicken filaments is temperature sensitive, and the myosin heads become disordered at temperatures near 4° C. At 25° C, however, thick filaments from chicken pectoralis muscle can be isolated with a well ordered, near-helical, arrangement of cross-bridges as seen in negatively stained preparations. This periodicity is confirmed by optical diffraction and computed transforms of images of the filaments. These show a strong series of layer lines near the orders of a 43 nm near-helical periodicity as expected from X-ray diffraction. Both analysis of phases on the first layer line, and computer filtered images of the filaments, are consistent with a three-stranded arrangement of the myosin heads on the filament.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00125312
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