Paramyosin and the filaments of molluscan “catch” muscles

The three-dimensional packing of molecules cannot be inferred, these results provide new information on the local packing relations of the molecules: 2-fold screw axes relate molecules—at least locally—in neighboring rows in a paramyosin filament

Carolyn Cohen


Key concepts

Scholarcy highlights

  • Aggregates of paramyosin precipitated with divalent cations show a variety of forms with simple staining patterns and a period of 725 Å in the electron microscope
  • All the forms may be generated from a basic polar array where the molecules do not bond end-to-end: dark staining regions represent “gap” areas where stain can penetrate the paracrystal; light regions are “overlap” areas where stain is largely excluded
  • The molecular length deduced from the band patterns is about 1275 Å, and is slightly different in paramyosins from different sources
  • Since the same basic arrays are found in paramyosins from different sources, there are similar specific interaction sites on these molecules
  • The “nodes” of the native net patterns can be interpreted as the dark staining gaps of the polar form, and the native net pattern can be generated by a regular shift of groups of molecules or subfilaments in the basic polar array
  • The tendency of paramyosin to form both polar and bipolar arrays has led to the prediction of bipolarity in the native filament

Need more features? Save interactive summary cards to your Scholarcy Library.