18] Preparation and characterization of adenylate cyclase from heart and skeletal muscle

Abstract

Publisher Summary Adenylate cyclase in heart and skeletal muscle is almost entirely bound to cellular membranes which sediment at low gravitational forces. It is generally recognized that the enzyme is located predominantly in plasma membranes of most cells and tissues. Evidence exists, however, that some adenylate cyclase activity is present in cardiac sareoplasmic reticulum. It has been studied in a microsomal fraction of rabbit muscle, and Rabinowitz have reported that the enzyme in this tissue is distributed largely in mitochondrial and microsomal fractions. The precise quantitative cellular localization of the enzyme is not settled. Most studies on kinetic properties and hormonal stimulation have been performed on washed particulate preparations sedimenting at low gravitational forces: 1000–2000 g.