Isolation and characterization of cGMP phosphodiesterase from bovine rod outer segments

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Publication Type Journal Article
School or College School of Medicine
Department Ophthalmology
Creator Baehr, Wolfgang
Other Author Devlin, M. J.; Applebury, M. L.
Title Isolation and characterization of cGMP phosphodiesterase from bovine rod outer segments
Date 1979
Description A simple purification method has been developed for isolation of bovine cGMP phosphodiesterase from photoreceptor rod outer segments. The enzyme is peripherally membrane bound in its native state and is present in relatively high concentrations. In the bovine photoreceptors its molar ratio to rhodopsin can be estimated to be as great as 1:40 and not lower than 1: 170. The isolated enzyme is purified to homogeneity as demonstrated by gel electrophoresis under native and denaturing conditions and analytical ultracentrifuga- Con. The core enzyme has a molecular weight of approximately 170,000, as demonstrated by sucrose gradient centrifugation and analytical ultracentrifugation, and is composed of two major subunits, 88,000 (CY) and 84,000 (p), augmented by a small subunit of 13,000 (y). In its purified state, the enzyme is activated neither by light nor GTP in contrast to the native membranebound enzyme. As isolated, the molar activity of the enzyme is 45 mol of cGMP hydrolized s-' mol-' with a Km = 150 PM (cGMP) and Km > 4 XnM (CAMP). Protamine activates the enzyme to 360 mol of cGMP see-' mol-' @-fold) and limited digestion by trypsin activates it to as great as 2100 mol of cGMP s-l mol-' @O-fold).
Type Text
Publisher American Society for Biochemistry and Molecular Biology (ASBMB)
Volume 254
Issue 22
First Page 11699
Last Page 11677
Subject Enzyme Activation; Macromolecular Substances; Trypsin/pharmacology
Subject MESH 3',5'-Cyclic-GMP Phosphodiesterase; Photoreceptors
Language eng
Bibliographic Citation Baehr W, Devlin MJ, Applebury ML. (1979). Isolation and characterization of cGMP phosphodiesterase from bovine rod outer segments. J Biol Chem, 254(22), 11699-77
Rights Management (c)American Society for Biochemistry and Molecular Biology (ASBMB)
Format Medium application/pdf
Identifier ir-main,1709
ARK ark:/87278/s6x64567
Setname ir_uspace
Date Created 2012-06-13
Date Modified 2012-06-13
ID 703771
Reference URL https://collections.lib.utah.edu/ark:/87278/s6x64567
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