DETOXICATIVE ENZYME ACTIVITIES IN FIVE SPECIES OF FIELD-COLLECTED MELANOPLINE GRASSHOPPERS (ORTHOPTERA: ACRIDIDAE)

1996 ◽  
Vol 128 (2) ◽  
pp. 353-354 ◽  
Author(s):  
Murray B. Isman ◽  
Ruying Feng ◽  
Dan L. Johnson
Keyword(s):  
Cytochrome P450 ◽  
Insecticide Resistance ◽  
Host Plant ◽  
Enzyme Activities ◽  
Cytochrome P450 Monooxygenases ◽  
Insect Host ◽  
Suitable Host ◽  
P450 Monooxygenases ◽  
Enzyme Systems ◽  
General Esterases

Detoxicative enzyme systems, such as the cytochrome P450 monooxygenases, gluthione S-transferases, and general esterases, have been widely studied in holometabolous insects (e.g. Lepidoptera, Diptera, and Coleoptera). These, and other enzyme systems, play important roles in insecticide resistance, but are also important in insect–host plant relationships, because host range can partially depend on the ability of an insect to cope with putatively toxic allelochemicals in an otherwise suitable host plant (e.g. Lindroth 1989). In some cases, differences in the relative activities of these enzymes between closely related insect taxa can have significant biological consequences (Siegfried and Mullin 1989).

scholarly journals The Role of Cytochrome P450s in Insect Toxicology and Resistance

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Ralf Nauen ◽  
Chris Bass ◽  
René Feyereisen ◽  
John Vontas
Keyword(s):  
Cytochrome P450 ◽  
Insecticide Resistance ◽  
Insect Pests ◽  
Cytochrome P450s ◽  
Cytochrome P450 Monooxygenases ◽  
Annual Review ◽  
Publication Date ◽  
Beneficial Insects ◽  
P450 Monooxygenases

Insect cytochrome P450 monooxygenases (P450s) perform a variety of important physiological functions, but it is their role in the detoxification of xenobiotics, such as natural and synthetic insecticides, that is the topic of this review. Recent advances in insect genomics and postgenomic functional approaches have provided an unprecedented opportunity to understand the evolution of insect P450s and their role in insect toxicology. These approaches have also been harnessed to provide new insights into the genomic alterations that lead to insecticide resistance, the mechanisms by which P450s are regulated, and the functional determinants of P450-mediated insecticide resistance. In parallel, an emerging body of work on the role of P450s in defining the sensitivity of beneficial insects to insecticides has been developed. The knowledge gained from these studies has applications for the management of P450-mediated resistance in insect pests and can be leveraged to safeguard the health of important beneficial insects. Expected final online publication date for the Annual Review of Entomology, Volume 67 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Cytochrome P450 monooxygenases and insecticide resistance in insects

1998 ◽  
Vol 353 (1376) ◽  
pp. 1701-1705 ◽  
Author(s):  
J. Bergé ◽  
R. Feyereisen ◽  
M. Amichot
Keyword(s):  
Cytochrome P450 ◽  
Insecticide Resistance ◽  
3D Structure ◽  
Resistance Mechanisms ◽  
Cytochrome P450 Monooxygenases ◽  
Wild Type ◽  
P450 Gene ◽  
P450 Monooxygenases ◽  
Loss Of Resistance ◽  
Cytochrome P450 Genes

Cytochrome P450 monooxygenases are involved in many cases of resistance of insects to insecticides. Resistance has long been associated with an increase in monooxygenase activities and with an increase in cytochrome P450 content. However, this increase does not always account for all of the resistance. In Drosophila melanogaster , we have shown that the overproduction of cytochrome P450 can be lost by the fly without a corresponding complete loss of resistance. These results prompted the sequencing of a cytochrome P450 candidate for resistance in resistant and susceptible flies. Several mutations leading to amino–acid substitutions have been detected in the P450 gene CYP6A2 of a resistant strain. The location of these mutations in a model of the 3D structure of the CYP6A2 protein suggested that some of them may be important for enzyme activity of this molecule. This has been verified by heterologous expression of wild–type and mutated cDNA in Escherichia coli . When other resistance mechanisms are considered, relatively few genetic mutations are involved in insecticide resistance, and this has led to an optimistic view of the management of resistance. Our observations compel us to survey in more detail the genetic diversity of cytochrome P450 genes and alleles involved in resistance.

Characterization of cytochrome P450-monooxygenases of Chinese hamsters with respect to aflatoxin B1 activation

Toxicology ◽  
1994 ◽  
Vol 93 (2-3) ◽  
pp. 165-173 ◽  
Author(s):  
Morio Fukuhara ◽  
Eric Antignac ◽  
Naomi Fukusen ◽  
Kazue Kato ◽  
Masanobu Kimura
Keyword(s):  
Cytochrome P450 ◽  
Aflatoxin B1 ◽  
Cytochrome P450 Monooxygenases ◽  
P450 Monooxygenases ◽  
Chinese Hamsters

scholarly journals Specificity and mechanism of carbohydrate demethylation by cytochrome P450 monooxygenases

2018 ◽  
Vol 475 (23) ◽  
pp. 3875-3886 ◽  
Author(s):  
Craig S. Robb ◽  
Lukas Reisky ◽  
Uwe T. Bornscheuer ◽  
Jan-Hendrik Hehemann
Keyword(s):  
Cytochrome P450 ◽  
Active Site ◽  
Substrate Recognition ◽  
High Energy ◽  
Cytochrome P450 Monooxygenases ◽  
P450 Monooxygenases ◽  
High Energy Barrier ◽  
Molecular Determinants ◽  
Cytochrome P450 Family ◽  
Carbohydrate Ligand

Degradation of carbohydrates by bacteria represents a key step in energy metabolism that can be inhibited by methylated sugars. Removal of methyl groups, which is critical for further processing, poses a biocatalytic challenge because enzymes need to overcome a high energy barrier. Our structural and computational analysis revealed how a member of the cytochrome P450 family evolved to oxidize a carbohydrate ligand. Using structural biology, we ascertained the molecular determinants of substrate specificity and revealed a highly specialized active site complementary to the substrate chemistry. Invariance of the residues involved in substrate recognition across the subfamily suggests that they are critical for enzyme function and when mutated, the enzyme lost substrate recognition. The structure of a carbohydrate-active P450 adds mechanistic insight into monooxygenase action on a methylated monosaccharide and reveals the broad conservation of the active site machinery across the subfamily.

scholarly journals Biotechnological Methods of Sulfoxidation: Yesterday, Today, Tomorrow

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 624 ◽  
Author(s):  
Wanda Mączka ◽  
Katarzyna Wińska ◽  
Małgorzata Grabarczyk
Keyword(s):  
Cytochrome P450 ◽  
Chemical Industry ◽  
Functional Materials ◽  
Cytochrome P450 Monooxygenases ◽  
Whole Cells ◽  
Historical Significance ◽  
P450 Monooxygenases ◽  
Bacteria And Fungi ◽  
Positive Results ◽  
Huge Variety

The production of chiral sulphoxides is an important part of the chemical industry since they have been used not only as pharmaceuticals and pesticides, but also as catalysts or functional materials. The main purpose of this review is to present biotechnological methods for the oxidation of sulfides. The work consists of two parts. In the first part, examples of biosyntransformation of prochiral sulfides using whole cells of bacteria and fungi are discussed. They have more historical significance due to the low predictability of positive results in relation to the workload. In the second part, the main enzymes responsible for sulfoxidation have been characterized such as chloroperoxidase, dioxygenases, cytochrome flavin-dependent monooxygenases, and P450 monooxygenases. Particular emphasis has been placed on the huge variety of cytochrome P450 monooxygenases, and flavin-dependent monooxygenases, which allows for pure sulfoxides enantiomers effectively to be obtained. In the summary, further directions of research on the optimization of enzymatic sulfoxidation are indicated.

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