The polyene antibiotic filipin forms electron microscopically visible complexes with cholesterol. In skeletal muscle fibers the filipin complexes are found mainly in the surface plasmalemma and transverse tubules, as closely packed single units. In the sarcoplasmic reticulum the filipin complexes are much less common, occur as clusters, and have a pronounced predilection for the intermediate cisterna. The incidence and distribution of the filipin complexes in situ and in SR vesicles compares well with the quantitative chemical analysis of the cholesterol content in comparable subcellular fractions of skeletal muscle reported in the literature.
ASJC Scopus subject areas
- Molecular Biology