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. 1981 Mar;33(3):409–418. doi: 10.1016/S0006-3495(81)84903-X

Stereological analysis of freeze-fracture subfractions from skeletal muscle. I. Relative intrinsic protein. II. Relative lipid content and protein-to-lipid ratio.

D J Scales
PMCID: PMC1327438  PMID: 7225513

Abstract

Standard microsomal subfractions from biological tissues are not homogeneous but mixtures of membranes derived from the various cellular organelles. In the case of skeletal muscle, freeze-fracture replicas show both smooth concave faces and concave faces densely populated with 90-A particles. Stereological sampling techniques have been applied to such replicas and the relative surface area of sarcoplasmic reticulum (SR) membrane calculated. Expressions are derived that estimate the relative fraction of SR intrinsic protein and lipid as a function of the relative surface area. Although most of the protein in our subfraction is SR protein, a significant amount of lipid is non-SR lipid. The effect of this on measurements of the protein-to-lipid ratio is discussed.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Deamer D. W., Branton D. Fracture planes in an ice-bilayer model membrane system. Science. 1967 Nov 3;158(3801):655–657. doi: 10.1126/science.158.3801.655. [DOI] [PubMed] [Google Scholar]
  2. Deamer D. W., Leonard R., Tardieu A., Branton D. Lamellar and hexagonal lipid phases visualized by freeze-etching. Biochim Biophys Acta. 1970;219(1):47–60. doi: 10.1016/0005-2736(70)90060-x. [DOI] [PubMed] [Google Scholar]
  3. Eletr S., Inesi G. Phospholipid orientation in sarcoplasmic membranes: spin-label ESR and proton MNR studies. Biochim Biophys Acta. 1972 Sep 1;282(1):174–179. doi: 10.1016/0005-2736(72)90321-5. [DOI] [PubMed] [Google Scholar]
  4. Losa G. A., Weibel E. R., Bolender R. P. Integrated stereological and biochemical studies on hepatocytic membranes. III. Relative surface of endoplasmic reticulum membranes in microsomal fractions estimated on freeze-fracture preparations. J Cell Biol. 1978 Aug;78(2):289–308. doi: 10.1083/jcb.78.2.289. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Malouf N. N., Sommer J. R. Chicken dystrophy. The geometry of the transverse tubules. Am J Pathol. 1976 Aug;84(2):299–316. [PMC free article] [PubMed] [Google Scholar]
  6. Sabbadini R., Scales D., Inesi G. Ca-2+ transport and assembly of protein particles in sarcoplasmic membranes isolated from normal and dystrophic muscle. FEBS Lett. 1975 Jun 1;54(1):8–12. doi: 10.1016/0014-5793(75)81056-8. [DOI] [PubMed] [Google Scholar]
  7. Scales D. J., Sabbadini R. A. Microsomal T system: a stereological analysis of purified microsomes derived from normal and dystrophic skeletal muscle. J Cell Biol. 1979 Oct;83(1):33–46. doi: 10.1083/jcb.83.1.33. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Scales D., Giuseppeinesi Assembly of ATPase protein in sarcoplasmic reticulum membranes. Biophys J. 1976 Jul;16(7):735–751. doi: 10.1016/S0006-3495(76)85725-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Scales D., Sabbadini R., Inesi G. The involvement of sarcotubular membranes in genetic muscular dystrophy. Biochim Biophys Acta. 1977 Mar 17;465(3):535–549. doi: 10.1016/0005-2736(77)90271-1. [DOI] [PubMed] [Google Scholar]
  10. Weibel E. R., Losa G., Bolender R. P. Stereological method for estimating relative membrane surface area in freeze-fracture preparations of subcellular fractions. J Microsc. 1976 Aug;107(3):255–266. doi: 10.1111/j.1365-2818.1976.tb02447.x. [DOI] [PubMed] [Google Scholar]

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