Smooth muscle cell sarcolemma. Purification and properties of plasma membranes from the rat uterus |
| |
Authors: | JFrederick Krall Stanley G Korenman |
| |
Institution: | 1. Molecular Endocrinology Laboratory, Veterans Administration Hospital, Sepulveda, CA 91343, U.S.A.;2. Department of Medicine, UCLA San Fernando Valley Medical Program, University of California, Los Angeles, CA 90024 U.S.A. |
| |
Abstract: | A membrane fraction with sarcolemmal properties was purified from the smooth muscle layers (myometrium) of rat uterus by successive differential and equilibrium centrifugation in sucrose. The putative sarcolemmal fraction was identified by iodination with 125I]iodosulfanilic acid, had an equilibrium density of 1.15, and was enriched in enzyme activities usually associated with the plasma membrane including 5′-nucleotidase (EC 3.1.3.5) and (Na+ + K+) ATPase (EC 3.6.1.3). These membranes were free of mitochondrial or nuclear membrane contamination, suggesting the relative enrichment of sarcolemmal membranes in the fraction. Proteins of the membranes were heterogeneous with respect to molecular weight, but only a few were labelled when intact muscle was radioiodinated. Uniform resistance of sarcolemmal proteins to trypsin digestion and salt extraction suggested many are tightly bound or intrinsic membrane proteins and was a further indication of the homogeneity of membranes in this fraction. |
| |
Keywords: | Myometrium Smooth muscle Sarcolemma Plasma membrane (Equilibrium centrifugation) |
本文献已被 ScienceDirect 等数据库收录! |
|