Dolichyl‐Phosphate Phosphatase and Dolichyl‐Diphosphate Phosphatase in Rat‐Liver Microsomes

Dolichyl‐phosphate phosphatase and dolichyl‐diphosphate phosphatase activities of a liver‐cell microsomal preparation were solubilized by treatment with Triton X‐100. The I00000 × g supernatant was then passed through a column of Sepharose‐4B – concanavalin A. Both enzyme activities were found in th...

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Autores principales: BELOCOPITOW, E., BOSCOBOINIK, D.
Formato: JOUR
Materias:
enzyme
animal experiment
dolichol diphosphatase
dolichyl phosphatase
liver
liver microsome
rat
Animal
Hydrogen-Ion Concentration
Kinetics
Microsomes, Liver
Phosphodiesterase Inhibitors
Phospholipids
Phosphoric Monoester Hydrolases
Pyrophosphatases
Rats
Substrate Specificity
Temperature
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00142956_v125_n1_p167_BELOCOPITOW
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id todo:paper_00142956_v125_n1_p167_BELOCOPITOW
record_format dspace
spelling todo:paper_00142956_v125_n1_p167_BELOCOPITOW2023-10-03T14:11:47Z Dolichyl‐Phosphate Phosphatase and Dolichyl‐Diphosphate Phosphatase in Rat‐Liver Microsomes BELOCOPITOW, E. BOSCOBOINIK, D. enzyme animal experiment dolichol diphosphatase dolichyl phosphatase liver liver microsome rat Animal Hydrogen-Ion Concentration Kinetics Microsomes, Liver Phosphodiesterase Inhibitors Phospholipids Phosphoric Monoester Hydrolases Pyrophosphatases Rats Substrate Specificity Temperature Dolichyl‐phosphate phosphatase and dolichyl‐diphosphate phosphatase activities of a liver‐cell microsomal preparation were solubilized by treatment with Triton X‐100. The I00000 × g supernatant was then passed through a column of Sepharose‐4B – concanavalin A. Both enzyme activities were found in the percolate. This treatment eliminated inhibition by ATP and glucose 6‐phosphate in both phosphatase activities. In each case the activities were inhibited by higher concentrations of enzyme preparation due to the presence of phospho‐ lipids. The inhibitory effects of either phosphatidylcholine or phosphatidylethanolamine were due to competition for detergent. On the other hand, the effect produced by phosphatidic acid appeared to be different, since it did not change the optimal concentration of Triton X‐100 for the two enzymes. Dolichyl‐phosphate phosphatase was strongly inhibited by both Pi and PPi, whereas dolichyl‐diphosphate phosphatase was only slightly inhibited by Pi and not at all by PPi. Dolichyl‐diphosphate phosphatase was more inhibited by divalent cations than dolichyl‐phosphate phos‐ phatase. The apparent Km of dolichyl‐phosphate phosphatase for dolichyl phosphate was 0.15 mM. Dolichol also inhibited dolichyl‐phosphate phosphatase, but it produced a stronger inhibition on dolichyl‐diphosphate phosphatase. The inhibitory effect of dolichol was not entirely due to detergent competition. Copyright © 1982, Wiley Blackwell. All rights reserved JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00142956_v125_n1_p167_BELOCOPITOW
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic enzyme
animal experiment
dolichol diphosphatase
dolichyl phosphatase
liver
liver microsome
rat
Animal
Hydrogen-Ion Concentration
Kinetics
Microsomes, Liver
Phosphodiesterase Inhibitors
Phospholipids
Phosphoric Monoester Hydrolases
Pyrophosphatases
Rats
Substrate Specificity
Temperature
spellingShingle enzyme
animal experiment
dolichol diphosphatase
dolichyl phosphatase
liver
liver microsome
rat
Animal
Hydrogen-Ion Concentration
Kinetics
Microsomes, Liver
Phosphodiesterase Inhibitors
Phospholipids
Phosphoric Monoester Hydrolases
Pyrophosphatases
Rats
Substrate Specificity
Temperature
BELOCOPITOW, E.
BOSCOBOINIK, D.
Dolichyl‐Phosphate Phosphatase and Dolichyl‐Diphosphate Phosphatase in Rat‐Liver Microsomes
topic_facet enzyme
animal experiment
dolichol diphosphatase
dolichyl phosphatase
liver
liver microsome
rat
Animal
Hydrogen-Ion Concentration
Kinetics
Microsomes, Liver
Phosphodiesterase Inhibitors
Phospholipids
Phosphoric Monoester Hydrolases
Pyrophosphatases
Rats
Substrate Specificity
Temperature
description Dolichyl‐phosphate phosphatase and dolichyl‐diphosphate phosphatase activities of a liver‐cell microsomal preparation were solubilized by treatment with Triton X‐100. The I00000 × g supernatant was then passed through a column of Sepharose‐4B – concanavalin A. Both enzyme activities were found in the percolate. This treatment eliminated inhibition by ATP and glucose 6‐phosphate in both phosphatase activities. In each case the activities were inhibited by higher concentrations of enzyme preparation due to the presence of phospho‐ lipids. The inhibitory effects of either phosphatidylcholine or phosphatidylethanolamine were due to competition for detergent. On the other hand, the effect produced by phosphatidic acid appeared to be different, since it did not change the optimal concentration of Triton X‐100 for the two enzymes. Dolichyl‐phosphate phosphatase was strongly inhibited by both Pi and PPi, whereas dolichyl‐diphosphate phosphatase was only slightly inhibited by Pi and not at all by PPi. Dolichyl‐diphosphate phosphatase was more inhibited by divalent cations than dolichyl‐phosphate phos‐ phatase. The apparent Km of dolichyl‐phosphate phosphatase for dolichyl phosphate was 0.15 mM. Dolichol also inhibited dolichyl‐phosphate phosphatase, but it produced a stronger inhibition on dolichyl‐diphosphate phosphatase. The inhibitory effect of dolichol was not entirely due to detergent competition. Copyright © 1982, Wiley Blackwell. All rights reserved
format JOUR
author BELOCOPITOW, E.
BOSCOBOINIK, D.
author_facet BELOCOPITOW, E.
BOSCOBOINIK, D.
author_sort BELOCOPITOW, E.
title Dolichyl‐Phosphate Phosphatase and Dolichyl‐Diphosphate Phosphatase in Rat‐Liver Microsomes
title_short Dolichyl‐Phosphate Phosphatase and Dolichyl‐Diphosphate Phosphatase in Rat‐Liver Microsomes
title_full Dolichyl‐Phosphate Phosphatase and Dolichyl‐Diphosphate Phosphatase in Rat‐Liver Microsomes
title_fullStr Dolichyl‐Phosphate Phosphatase and Dolichyl‐Diphosphate Phosphatase in Rat‐Liver Microsomes
title_full_unstemmed Dolichyl‐Phosphate Phosphatase and Dolichyl‐Diphosphate Phosphatase in Rat‐Liver Microsomes
title_sort dolichyl‐phosphate phosphatase and dolichyl‐diphosphate phosphatase in rat‐liver microsomes
url http://hdl.handle.net/20.500.12110/paper_00142956_v125_n1_p167_BELOCOPITOW
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