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Evidence against a generalized membrane defect in dystrophic mice platelets
Author(s) -
Mizobe Fumio,
Livett Bruce G.
Publication year - 1982
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.880050509
Subject(s) - arrhenius plot , membrane , platelet , chemistry , muscular dystrophy , phospholipid , biophysics , enzyme , arrhenius equation , biochemistry , biology , medicine , activation energy , immunology , organic chemistry
The response of the membrane‐bound enzyme AChE to changes in temperatures was investigated to test the applicability of the “generalized membrane defect” hypothesis proposed for human myotonic and Duchenne muscular dystrophies to the two forms of muscular dystrophy expressed in mice. For intact platelets from homozygous normal and dystrophic mice of both strains, a break (Tc) occurred in the Arrhenius plot of AChE activity at approximately 22 C. Solubilization of membrane‐bound AChE by Triton X‐100 produced a nonlinear Arrhenius plot over the temperature range (7.7 C to 37 C) in normal and dystrophic mice of both strains. However, in the presence of phospholipase A 2 + C and Triton X‐100, a linear Arrhenius plot was produced indicating that the membrane‐bound enzyme is normally modulated by a bulk lipid domain as well as by a tightly bound (immobilized) phospholipid domain. The temperature response of platelet AChE from normal and dystrophic mice of both strains was not significantly different. These results showing normal temperature kinetics of AChE do not lend support to the theory of a membrane defect in the platelets of dystrophic mice.