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פותח על ידי קלירמאש פתרונות בע"מ -
Ecdysone 20‐monooxygenase in mitochondria and microsomes of Manduca sexta (L.) Midgut: Is the dual localization real?
Year:
1985
Authors :
סבובודה, ג'יימס
;
.
Volume :
2
Co-Authors:
Weirich, G.F., Insect Physiology Laboratory, Agricultural Research Service, Usda, Beltsville, Maryland, United States
Svoboda, J.A., Insect Physiology Laboratory, Agricultural Research Service, Usda, Beltsville, Maryland, United States
Thompson, M.J., Insect Physiology Laboratory, Agricultural Research Service, Usda, Beltsville, Maryland, United States
Facilitators :
From page:
385
To page:
396
(
Total pages:
12
)
Abstract:
The dual localization of ecdysone 20‐monooxygenase in mitochondria and microsomes of Manduca sexta larval midgut was investigated. Cosubstrate requirements and response to osmolarity of the microsomal ecdysone 20‐monooxygenase system were found to be different from those previously reported for the mitochondrial enzyme system. The microsomal monooxygenase utilized NADPH and, less efficiently, NADH as cosubstrates. NADPH and NADH effects were neither additive nor synergistic. NADPH yielded identical activities in isotonic and hypotonic incubations. Mitochondria and microsomes showed no synergistic interaction for ecdysone 20‐hydroxylation. After washing of the mitochondria, a large proportion of their ecdysone 20‐monooxygenase activity was lost. The extent of the loss was inversely correlated to the concentration of mitochondria in the incubation mixture. The addition of bovine serum albumin to the incubations (2 mg/ml) largely restored the original activities. The microsomal contamination in mitochondrial pellets after each of three successive washings was determined by measuring the activity of a microsomal marker enzyme, NADPH‐cytochrome c reductase. At each step of the purification, the ecdysone 20‐monooxgenase activity of the mitochondrial preparations far exceeded the activity attributable to the microsomal contamination. These results confirm the existence of two independent ecdysone 20‐monooxygenase systems in the midgut of M. sexta larvae. Copyright © 1985 Wiley‐Liss, Inc.
Note:
Related Files :
ecdysone 20‐monooxygenase
Manduca sexta
midgut
NADPH‐cytochrome c reductase
tobacco hornworm
עוד תגיות
תוכן קשור
More details
DOI :
10.1002/arch.940020406
Article number:
Affiliations:
Database:
סקופוס
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
23864
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:03
Scientific Publication
Ecdysone 20‐monooxygenase in mitochondria and microsomes of Manduca sexta (L.) Midgut: Is the dual localization real?
2
Weirich, G.F., Insect Physiology Laboratory, Agricultural Research Service, Usda, Beltsville, Maryland, United States
Svoboda, J.A., Insect Physiology Laboratory, Agricultural Research Service, Usda, Beltsville, Maryland, United States
Thompson, M.J., Insect Physiology Laboratory, Agricultural Research Service, Usda, Beltsville, Maryland, United States
Ecdysone 20‐monooxygenase in mitochondria and microsomes of Manduca sexta (L.) Midgut: Is the dual localization real?
The dual localization of ecdysone 20‐monooxygenase in mitochondria and microsomes of Manduca sexta larval midgut was investigated. Cosubstrate requirements and response to osmolarity of the microsomal ecdysone 20‐monooxygenase system were found to be different from those previously reported for the mitochondrial enzyme system. The microsomal monooxygenase utilized NADPH and, less efficiently, NADH as cosubstrates. NADPH and NADH effects were neither additive nor synergistic. NADPH yielded identical activities in isotonic and hypotonic incubations. Mitochondria and microsomes showed no synergistic interaction for ecdysone 20‐hydroxylation. After washing of the mitochondria, a large proportion of their ecdysone 20‐monooxygenase activity was lost. The extent of the loss was inversely correlated to the concentration of mitochondria in the incubation mixture. The addition of bovine serum albumin to the incubations (2 mg/ml) largely restored the original activities. The microsomal contamination in mitochondrial pellets after each of three successive washings was determined by measuring the activity of a microsomal marker enzyme, NADPH‐cytochrome c reductase. At each step of the purification, the ecdysone 20‐monooxgenase activity of the mitochondrial preparations far exceeded the activity attributable to the microsomal contamination. These results confirm the existence of two independent ecdysone 20‐monooxygenase systems in the midgut of M. sexta larvae. Copyright © 1985 Wiley‐Liss, Inc.
Scientific Publication
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