Abstract
Membranes were purified from rat muscle by a differential centrifugation method that avoids the use of salt extraction or incubations at elevated temperature. Three populations of membrane-limited vesicles were defined having average densities of 1.112 (fraction I), 1.141 (fraction II), and 1.158 (fraction III) g/ml in a continuous sucrose gradient. Lactoperoxidase-catalyzed iodination of intact muscle prior to isolation of membranes resulted in highest specific activity in fraction I, although all fractions could be equally labeled after isolation. 125I-Labeled wheat germ agglutinin incubated at low concentration with intact muscle preferentially labeled fraction I. Parallel studies on previously isolated fractions indicated that fraction I also contained the highest concentration of potential receptors for wheat germ agglutinin. In experiments on whole muscle, concanavalin A bound predominantly to sarcolemma with slight variable binding to T-tubular and nuclear membrane but no binding to sarcoplasmic reticulum or mitochondria. Parallel binding studies with isolated membrane fragments indicated heavy binding of concanavalin A by membranes in fraction I with scattered binding in fractions II and III. Na+K+Mg2+ ATPase was specifically enriched in fraction I but was also present in fraction II in a proportion similar to 125I labeling. Ca2+ ATPase was most active in fraction II but present in significant levels in fraction I. It is concluded from these and other data that fraction I contains predominantly sarcolemma membrane, while T-tubular membrane may represent a significant component of fraction II. Ca2+ ATPase activity in fraction I is intrinsic to the sarcolemma.
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- Andrew C. G., Appel S. H. Macromolecular characterization of muscle membranes. I. Proteins and sialic acid of normal and denervated muscle. J Biol Chem. 1973 Jul 25;248(14):5156–5163. [PubMed] [Google Scholar]
- Bernhard W., Avrameas S. Ultrastructural visualization of cellular carbohydrate components by means of concanavalin A. Exp Cell Res. 1971 Jan;64(1):232–236. doi: 10.1016/0014-4827(71)90217-5. [DOI] [PubMed] [Google Scholar]
- Cuatrecasas P. Interaction of wheat germ agglutinin and concanavalin A with isolated fat cells. Biochemistry. 1973 Mar 27;12(7):1312–1323. doi: 10.1021/bi00731a011. [DOI] [PubMed] [Google Scholar]
- Deamer D. W., Baskin R. J. Ultrastructure of sarcoplasmic reticulum preparations. J Cell Biol. 1969 Jul;42(1):296–307. doi: 10.1083/jcb.42.1.296. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Festoff B. W., Engel W. K. In vitro analysis of the general properties and junctional receptor characteristics of skeletal muscle membranes. Isolation, purification, and partial characterization of sarcolemmal fragments. Proc Natl Acad Sci U S A. 1974 Jun;71(6):2435–2439. doi: 10.1073/pnas.71.6.2435. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Franzini-Armstrong C. Studies of the triad. II. Penetration of tracers into the junctional gap. J Cell Biol. 1971 Apr;49(1):196–203. doi: 10.1083/jcb.49.1.196. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HESS H. H., LEWIN E. MICROASSAY OF BIOCHEMICAL STRUCTURAL COMPONENTS IN NERVOUS TISSUES. II. METHODS FOR CEREBROSIDES, PROTEOLIPID PROTEINS AND RESIDUE PROTEINS. J Neurochem. 1965 Mar;12:205–211. doi: 10.1111/j.1471-4159.1965.tb06756.x. [DOI] [PubMed] [Google Scholar]
- Kidwai A. M., Radcliffe M. A., Lee E. Y., Daniel E. E. Isolation and properties of skeletal muscle plasma membrane. Biochim Biophys Acta. 1973 Mar 29;298(3):593–607. doi: 10.1016/0005-2736(73)90076-x. [DOI] [PubMed] [Google Scholar]
- Rash J. E., Ellisman M. H. Studies of excitable membranes. I. Macromolecular specializations of the neuromuscular junction and the nonjunctional sarcolemma. J Cell Biol. 1974 Nov;63(2 Pt 1):567–586. doi: 10.1083/jcb.63.2.567. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sulakhe P. V., Drummond G. I., Ng D. C. Calcium binding by skeletal muscle sarcolemma. J Biol Chem. 1973 Jun 25;248(12):4150–4157. [PubMed] [Google Scholar]
- Weinstein D. B., Marsh J. B., Glick M. C., Warren L. Membranes of animal cells. IV. Lipids of the L cell and its surface membrane. J Biol Chem. 1969 Aug 10;244(15):4103–4111. [PubMed] [Google Scholar]
- Winzler R. J. Carbohydrates in cell surfaces. Int Rev Cytol. 1970;29:77–125. doi: 10.1016/s0074-7696(08)60033-9. [DOI] [PubMed] [Google Scholar]