Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1977 Jan;74(1):34-8.
doi: 10.1073/pnas.74.1.34.

Isolation and characterization of muscle membranes using surface-specific labels

Isolation and characterization of muscle membranes using surface-specific labels

R L Barchi et al. Proc Natl Acad Sci U S A. 1977 Jan.

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.

PubMed Disclaimer

Similar articles

Cited by

References

    1. J Neurochem. 1965 Mar;12:205-11 - PubMed
    1. J Cell Biol. 1971 Apr;49(1):196-203 - PubMed
    1. J Cell Biol. 1974 Nov;63(2 Pt 1):567-86 - PubMed
    1. J Cell Biol. 1969 Jul;42(1):296-307 - PubMed
    1. J Biol Chem. 1973 Jun 25;248(12):4150-7 - PubMed

Publication types

LinkOut - more resources