Open AccessIsolation from Thyroid Cells of Purified Plasma Membranes with Associated Actin Microfilaments
Author(s) -
REGNOUF Francoise,
DELOBBE André,
GABRION Jacqueline,
MESNIER Danielle,
PRADEL LouiseAnne
Publication year - 1982
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1982.tb05861.x
Subject(s) - heavy meromyosin , membrane , microfilament , actin , myosin , chemistry , cytoskeleton , biochemistry , biophysics , biology , cell
Plasma membranes of thyroid cells were purified from hog thyroid glands following two procedures. Their homogeneity was tested by electron microscopy and by measurements of the activity of membrane‐bound enzyme markers. According to the procedure used the membrane fractions obtained present some differences in their morphological features as well as in the repartition of the activities of the membrane‐bound enzyme markers. However, whatever the composition of the membrane fraction examined (membrane vesicles, single membrane sheets with junctional complexes), decoration with heavy meromyosin clearly shows the presence of actin filaments attached to these fragments. Analysis of proteins by polyacrylamide gel electrophoresis indicates the presence of about twelve major components with actin. Treatment of membranes with Triton X‐100 results in an insoluble core which contains all the actin and most of the major proteins. The selective extraction of these components by buffers differing in their ionic strength, pH, or the presence or absence of ATP. Mg has been used to characterize some of the proteins associated to actin; among them are filamin, myosin, α‐actinin, tropomyosin.