Abstract
Chicken liver microsomal fractions show lactate and malate dehydrogenase activities which behave differently with respect to successive extractions by sonication in 0.15 M NaCl, 0.2% Triton X-100 and 0.15 M NaCl, respectively. The Triton X-100-treated pellet did not show malate dehydrogenase activity but exhibited a 10-fold increase in lactate dehydrogenase activity with respect to the sonicated pellet. Total extracted lactate and malate dehydrogenase activities were, respectively, 7.5 and 1.7 times higher than that in the initial pellet. Different isoenzyme compositions were observed for cytosoluble and microsomal extracted lactate and malate dehydrogenases. When the ionic strength (0–500 mM) or the pH values (6.1–8.7) of the media were increased, an efficient release of lactate dehydrogenase was found at NaCl 30–70 mM and pH 6.6–7.3. Malate dehydrogenase solubilization under the same conditions was very small, even at NaCl 500 mM, but it attained a maximum in the 7.3–8.7 pH range. Cytosoluble lactate dehydrogenase bound in vitro to 0.15 M NaCl-treated (M 2) and sonicated (M 3) microsomal fractions but not to the crude microsomal fraction (M 1). Particle saturation by lactate dehydrogenase occurred with M 2 and M 3, which contained binding sites with different affinities. Cytosoluble malate dehydrogenase did not bind to M 1, M 2 and M 3 fractions, however, a little binding was found when purified basic malate dehydrogenase was incubated with M 2 or M 3 fractions.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.