scholarly journals The Isoenzymic Diketocamphane Monooxygenases of Pseudomonas putida ATCC 17453—An Episodic History and Still Mysterious after 60 Years

2021 ◽  
Vol 9 (12) ◽  
pp. 2593
Author(s):  
Andrew Willetts
Keyword(s):  
Pseudomonas Putida ◽  
Current Knowledge ◽  
Chemical Oxidation ◽  
Ring Cleavage ◽  
Catabolic Pathway ◽  
Naturally Occurring ◽  
Mistaken Belief ◽  
Two Component ◽  
History Of ◽  
The Many

Researching the involvement of molecular oxygen in the degradation of the naturally occurring bicyclic terpene camphor has generated a six-decade history of fascinating monooxygenase biochemistry. While an extensive bibliography exists reporting the many varied studies on camphor 5-monooxygenase, the initiating enzyme of the relevant catabolic pathway in Pseudomonas putida ATCC 17453, the equivalent recorded history of the isoenzymic diketocamphane monooxygenases, the enzymes that facilitate the initial ring cleavage of the bicyclic terpene, is both less extensive and more enigmatic. First referred to as ‘ketolactonase—an enzyme for cyclic lactonization’—the enzyme now classified as 2,5-diketocamphane 1,2-monooxygenase (EC 1.14.14.108) holds a special place in the history of oxygen-dependent biochemistry, being the first biocatalyst confirmed to undertake a biooxygenation reaction equivalent to the peracid-catalysed Baeyer–Villiger chemical oxidation first reported in the late 19th century. However, following that auspicious beginning, the biochemistry of EC 1.14.14.108, and its isoenzymic partner 3,6-diketocamphane 1,6-monooxygenase (EC 1.14.14.155) was dogged for many years by the mistaken belief that the enzymes were true flavoproteins that function with a tightly-bound flavin cofactor in the active site. This misconception led to a number of erroneous interpretations of relevant experimental data. It is only in the last decade, initially as the result of pure serendipity, that these enzymes have been confirmed to be members of a relatively recently discovered class of oxygen-dependent enzymes, the flavin-dependent two-component monooxygenases. This has promoted a renaissance of interest in the enzymes, resulting in programmes of research that have significantly expanded current knowledge of both their mode of action and regulation in camphor-grown P. putida ATCC 17453. However, some features of the biochemistry of the isoenzymic diketocamphane monooxygenases remain currently unexplained. It is the episodic history of these enzymes and some of what remains unresolved that are the principal subjects of this review.

Salt: Fragments from the History of a Medium

2020 ◽  
Vol 37 (6) ◽  
pp. 135-158
Author(s):  
Liam Cole Young
Keyword(s):  
Supply Chains ◽  
Digital Culture ◽  
Common Salt ◽  
Cultural Expression ◽  
Nature And Culture ◽  
Naturally Occurring ◽  
History Of ◽  
Material Turn ◽  
General Material ◽  
The Many

This essay explores histories of common salt, sodium chloride, using concepts and methods from media theory. It contributes to research on media and environment and the general ‘material turn’ taken across the Humanities. I conceive of salt as what Peters calls an ‘elemental’ medium so as to show, first, the imbrication of naturally-occurring substances in the operations and supply chains of digital culture. Second, the many lives salt has lived materially, in techniques of survival and exchange, and metaphorically, in cultural expression, complicate conventional understandings of media. In showing how salt performs three functions, processing, storage, and transfer, which Kittler ascribed to technical and symbolic media, I argue for a more expansive use of ‘mediation’ as a bridge concept that speaks to matters of nature and culture, Arts and Science, and to account for deep histories of extraction and economy that shape digital culture and global supply chains.

scholarly journals The Two-Component Monooxygenase MeaXY Initiates the Downstream Pathway of Chloroacetanilide Herbicide Catabolism in Sphingomonads

2017 ◽  
Vol 83 (7) ◽  
Author(s):  
Minggen Cheng ◽  
Qiang Meng ◽  
Youjian Yang ◽  
Cuiwei Chu ◽  
Qing Chen ◽  
...  
Keyword(s):  
Ring Cleavage ◽  
Monooxygenase System ◽  
Biochemical Pathway ◽  
Catabolic Pathway ◽  
Aniline Derivative ◽  
Content Type ◽  
The Past ◽  
Chloroacetanilide Herbicides ◽  
Two Component ◽  
Key Genes

ABSTRACT Due to the extensive use of chloroacetanilide herbicides over the past 60 years, bacteria have evolved catabolic pathways to mineralize these compounds. In the upstream catabolic pathway, chloroacetanilide herbicides are transformed into the two common metabolites 2-methyl-6-ethylaniline (MEA) and 2,6-diethylaniline (DEA) through N-dealkylation and amide hydrolysis. The pathway downstream of MEA is initiated by the hydroxylation of aromatic rings, followed by its conversion to a substrate for ring cleavage after several steps. Most of the key genes in the pathway have been identified. However, the genes involved in the initial hydroxylation step of MEA are still unknown. As a special aniline derivative, MEA cannot be transformed by the aniline dioxygenases that have been characterized. Sphingobium baderi DE-13 can completely degrade MEA and use it as a sole carbon source for growth. In this work, an MEA degradation-deficient mutant of S. baderi DE-13 was isolated. MEA catabolism genes were predicted through comparative genomic analysis. The results of genetic complementation and heterologous expression demonstrated that the products of meaX and meaY are responsible for the initial step of MEA degradation in S. baderi DE-13. MeaXY is a two-component flavoprotein monooxygenase system that catalyzes the hydroxylation of MEA and DEA using NADH and flavin mononucleotide (FMN) as cofactors. Nuclear magnetic resonance (NMR) analysis confirmed that MeaXY hydroxylates MEA and DEA at the para-position. Transcription of meaX was enhanced remarkably upon induction of MEA or DEA in S. baderi DE-13. Additionally, meaX and meaY were highly conserved among other MEA-degrading sphingomonads. This study fills a gap in our knowledge of the biochemical pathway that carries out mineralization of chloroacetanilide herbicides in sphingomonads. IMPORTANCE Much attention has been paid to the environmental fate of chloroacetanilide herbicides used for the past 60 years. Microbial degradation is considered an important mechanism in the degradation of these compounds. Bacterial degradation of chloroacetanilide herbicides has been investigated in many recent studies. Pure cultures or consortia able to mineralize these herbicides have been obtained. The catabolic pathway has been proposed, and most key genes involved have been identified. However, the genes responsible for the initiation step (from MEA to hydroxylated MEA or from DEA to hydroxylated DEA) of the downstream pathway have not been reported. The present study demonstrates that a two-component flavin-dependent monooxygenase system, MeaXY, catalyzes the para-hydroxylation of MEA or DEA in sphingomonads. Therefore, this work finds a missing link in the biochemical pathway that carries out the mineralization of chloroacetanilide herbicides in sphingomonads. Additionally, the results expand our understanding of the degradation of a special kind of aniline derivative.

A 200-Year History of the Study of Childhood Language Disorders of Unknown Origin: Changes in Terminology

2020 ◽  
Vol 5 (1) ◽  
pp. 6-11 ◽  
Author(s):  
Laurence B. Leonard
Keyword(s):  
Language Impairment ◽  
Specific Language Impairment ◽  
Scientific Literature ◽  
Language Disorder ◽  
Language Disorders ◽  
Unknown Origin ◽  
Developmental Language Disorder ◽  
The Past ◽  
History Of ◽  
The Many

Purpose The current “specific language impairment” and “developmental language disorder” discussion might lead to important changes in how we refer to children with language disorders of unknown origin. The field has seen other changes in terminology. This article reviews many of these changes. Method A literature review of previous clinical labels was conducted, and possible reasons for the changes in labels were identified. Results References to children with significant yet unexplained deficits in language ability have been part of the scientific literature since, at least, the early 1800s. Terms have changed from those with a neurological emphasis to those that do not imply a cause for the language disorder. Diagnostic criteria have become more explicit but have become, at certain points, too narrow to represent the wider range of children with language disorders of unknown origin. Conclusions The field was not well served by the many changes in terminology that have transpired in the past. A new label at this point must be accompanied by strong efforts to recruit its adoption by clinical speech-language pathologists and the general public.

Heracles and epilepsy: the sacred disease

2020 ◽  
Vol 78 (10) ◽  
pp. 660-662
Author(s):  
Eduardo ORREGO-GONZÁLEZ ◽  
Ana PERALTA-GARCÍA ◽  
Leonardo PALACIOS-SÁNCHEZ
Keyword(s):  
Current Knowledge ◽  
Greek Mythology ◽  
Corpus Hippocraticum ◽  
Ancient Times ◽  
The Many

ABSTRACT Epilepsy is one of the most dreaded and terrifying human afflictions. One of the many names it has received was Sacred Disease, during Greek times. Heracles served as a source of the divine connotation that epilepsy received in ancient times, as he was one of the most important demigods in Greek mythology. However, several authors have attributed Heracles’ actions to a seizure, including Hippocrates, who described the sacred disease on his “Corpus Hippocraticum.” This paper reviewed some of the publications on the myth and content of the text of Hippocrates, in relation to the current knowledge of the disease.

Paleontology and stratigraphy of Middle Eocene rock units in the southern Green River and Uinta Basins, Wyoming and Utah

2017 ◽  
Vol 4 ◽  
pp. 1-53 ◽  
Author(s):  
Paul Murphey ◽  
K.E. Townsend ◽  
Anthony Friscia ◽  
James Westgate ◽  
Emmett Evanoff ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Middle Eocene ◽  
Green River Basin ◽  
Green River ◽  
Scientific Exploration ◽  
History Of ◽  
Climatic History ◽  
Field Excursion ◽  
Land Mammal ◽  
Bridger Formation

The Bridger Formation is restricted to the Green River Basin in southwest Wyoming, and the Uinta and Duchesne River Formations are located in the Uinta Basin in Utah. These three rock units and their diverse fossil assemblages are of great scientific importance and historic interest to vertebrate paleontologists. Notably, they are also the stratotypes from oldest to youngest for the three middle Eocene North American Land Mammal Ages—the Bridgerian, Uintan, and Duchesnean. The fossils and sediments of these formations provide a critically important record of biotic, environmental, and climatic history spanning approximately 10 million years (49 to 39 Ma). This article provides a detailed field excursion through portions of the Green River and Uinta Basins that focuses on locations of geologic, paleontologic, and historical interest. In support of the field excursion, we also provide a review of current knowledge of these formations with emphasis on lithostratigraphy, biochronology, depositional, and paleoenvironmental history, and the history of scientific exploration.

ARTISTIC AND AESTHETIC EDUCATION AND MUSICAL PSYCHOTHERAPY OF A SPECIALIST’S TRAINING

2020 ◽  
Vol 384 (2) ◽  
pp. 222-232
Author(s):  
P. V. Menshikov ◽  
G. K. Kassymova ◽  
R. R. Gasanova ◽  
Y. V. Zaichikov ◽  
V. A. Berezovskaya ◽  
...  
Keyword(s):  
Performance Practice ◽  
Piano Music ◽  
Traumatic Experiences ◽  
Special Role ◽  
Native Culture ◽  
History Of ◽  
The Subject ◽  
And Performance ◽  
The Many ◽  
Special Meaning

A special role in the development of a pianist as a musician, composer and performer, as shown by the examples of the well-known, included in the history of art, and the most ordinary pianists, their listeners and admirers, lovers of piano music and music in general, are played by moments associated with psychotherapeutic abilities and music features. The purpose of the study is to comprehend the psychotherapeutic aspects of performing activities (using pianists as an example). The research method is a theoretical analysis of the psychotherapeutic aspects of performing activities: the study of the possibilities and functions of musical psychotherapy in the life of a musician as a “(self) psychotherapist” and “patient”. For almost any person, music acts as a way of self-understanding and understanding of the world, a way of self-realization, rethinking and overcoming life's difficulties - internal and external "blockages" of development, a way of saturating life with universal meanings, including a person in the richness of his native culture and universal culture as a whole. Art and, above all, its metaphorical nature help to bring out and realize internal experiences, provide an opportunity to look at one’s own experiences, problems and injuries from another perspective, to see a different meaning in them. In essence, we are talking about art therapy, including the art of writing and performing music - musical psychotherapy. However, for a musician, music has a special meaning, special significance. Musician - produces music, and, therefore, is not only an “object”, but also the subject of musical psychotherapy. The musician’s training includes preparing him as an individual and as a professional to perform functions that can be called psychotherapeutic: in the works of the most famous performers, as well as in the work of ordinary teachers, psychotherapeutic moments sometimes become key. Piano music and performance practice sets a certain “viewing angle” of life, and, in the case of traumatic experiences, a new way of understanding a difficult, traumatic and continuing to excite a person event, changing his attitude towards him. It helps to see something that was hidden in the hustle and bustle of everyday life or in the patterns of relationships familiar to a given culture. At the same time, while playing music or learning to play music, a person teaches to see the hidden and understand the many secrets of the human soul, the relationships of people.

Integration of Ecological and Engineering Aspects in Planning Large Scale Tidal Power Development in the Bay of Fundy, Canada

1984 ◽  
Vol 16 (1-2) ◽  
pp. 281-295 ◽  
Author(s):  
Donald C Gordon
Keyword(s):  
Large Scale ◽  
Feasibility Studies ◽  
Bay Of Fundy ◽  
Final Decision ◽  
Power Development ◽  
Tidal Power ◽  
History Of ◽  
Scientists And Engineers ◽  
The Many ◽  
University Scientists

Large-scale tidal power development in the Bay of Fundy has been given serious consideration for over 60 years. There has been a long history of productive interaction between environmental scientists and engineers durinn the many feasibility studies undertaken. Up until recently, tidal power proposals were dropped on economic grounds. However, large-scale development in the upper reaches of the Bay of Fundy now appears to be economically viable and a pre-commitment design program is highly likely in the near future. A large number of basic scientific research studies have been and are being conducted by government and university scientists. Likely environmental impacts have been examined by scientists and engineers together in a preliminary fashion on several occasions. A full environmental assessment will be conducted before a final decision is made and the results will definately influence the outcome.

THE ROLE OF NON-GOVERNMENTAL ORGANIZATIONS (NGOs) AS INTERMEDIARIES OF THE EUROPEAN UNION DECISION TO ADOPT INTERNATIONAL ACCOUNTING STANDARDS: 1973–2002

2016 ◽  
Vol 43 (2) ◽  
pp. 59-127 ◽  
Author(s):  
Devrimi Kaya ◽  
Robert J. Kirsch ◽  
Klaus Henselmann
Keyword(s):  
European Union ◽  
Accounting Standards ◽  
International Accounting ◽  
International Accounting Standards ◽  
The European Union ◽  
Governmental Organizations ◽  
Non Governmental Organizations ◽  
History Of ◽  
The Many

This paper analyzes the role of non-governmental organizations (NGOs) as intermediaries in encouraging the European Union (EU) to adopt International Accounting Standards (IAS). Our analysis begins with the 1973 founding of the International Accounting Standards Committee (IASC), and ends with 2002 when the binding EU regulation was approved. We document the many pathways of interaction between European supranational, governmental bodies and the IASC/IASB, as well as important regional NGOs, such as the Union Européenne des Experts Comptables, Économiques et Financiers (UEC), the Groupe d'Etudes des Experts Comptables de la Communauté Économique Européenne (Groupe d'Etudes), and their successor, the Fédération des Experts Comptables Européens (FEE). This study investigates, through personal interviews of key individuals involved in making the history of the organizations studied, and an extensive set of primary sources, how NGOs filled key roles in the process of harmonization of international accounting standards.

State-Sponsored Inequality

2017 ◽  
Author(s):  
Shuang Chen
Keyword(s):  
Qing Dynasty ◽  
Social Stratification ◽  
Social Hierarchy ◽  
The State ◽  
Structural Inequality ◽  
Political Hierarchy ◽  
History Of ◽  
Agrarian Societies ◽  
Stratification System ◽  
The Many

The book explores the social economic processes of inequality produced by differential state entitlements. Drawing on uniquely rich source materials from central and local archives, the book provides an unprecedented, comprehensive view of the creation of a socio-economic and political hierarchy under the Eight Banners in the Qing dynasty in what is now Shuangcheng County, Heilongjiang province. Shuangcheng was settled by bannermen from urban Beijing and elsewhere in rural Manchuria in the nineteenth century. The state classified the immigrants into distinct categories, each associated with differentiated land entitlements. By reconstructing the history of settlement and land distribution in this county, the book shows that patterns of wealth stratification and the underlying social hierarchy were not merely imposed by the state from the top-down but created and reinforced by local people through practices on the ground. In the course of pursuing their own interests, settlers internalized the distinctions created by the state through its system of unequal land entitlements. The tensions built into the unequal land entitlements therefore shaped the identities of immigrant groups, and this social hierarchy persisted after the fall of the Qing in 1911. The book offers an in-depth understanding of the key factors that contributed to social stratification in agrarian societies in the nineteenth- and early twentieth-century China. Moreover, it also sheds light on the many parallels between the stratification system in Qing-dynasty Shuangcheng and the structural inequality in contemporary China.

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