Fish myofibrillar protein and lipid interaction in aqueous media as detected by isotope labeling, sucrose gradient centrifugation, polyacrylamide electrophoresis and electron paramagnetic resonance

Structural organization of filamentous proteins in postsynaptic density

Actin is one of the major protein constituents of the postsynaptic density (PSD), a characteristic structural entity subjacent to the postsynaptic membrane in excitatory synapses of the vertebrate central nervous system. In isolated purified PSD preparations, it is present to the extent of 29 +/- 2 micrograms/mg of total protein, 90% of which is in the filamentous (F-actin) form. Iodination by a discriminatory labeling technique demonstrates that actin is located on the surface of the PSD from which it can be stripped by treatment with a mixture of strong anionic detergents, leaving behind an insoluble core held together by disulfide bridges, consisting in part of tubulin and "PSD protein".