scholarly journals PpoC from Aspergillus nidulans is a fusion protein with only one active haem

2010 ◽  
Vol 425 (3) ◽  
pp. 553-565 ◽  
Author(s):  
Florian Brodhun ◽  
Stefan Schneider ◽  
Cornelia Göbel ◽  
Ellen Hornung ◽  
Ivo Feussner
Keyword(s):  
Linoleic Acid ◽  
Aspergillus Nidulans ◽  
Octadecadienoic Acid ◽  
Terminal Region ◽  
Site Directed Mutagenesis ◽  
Isomerase Activity ◽  
Parallel Decomposition ◽  
Hydroxyoctadecadienoic Acid ◽  
Epoxy Alcohols ◽  
Hydroperoxyoctadecadienoic Acid

In Aspergillus nidulans Ppos [psi (precocious sexual inducer)-producing oxygenases] are required for the production of so-called psi factors, compounds that control the balance between the sexual and asexual life cycle of the fungus. The genome of A. nidulans harbours three different ppo genes: ppoA, ppoB and ppoC. For all three enzymes two different haem-containing domains are predicted: a fatty acid haem peroxidase/dioxygenase domain in the N-terminal region and a P450 haem-thiolate domain in the C-terminal region. Whereas PpoA was shown to use both haem domains for its bifunctional catalytic activity (linoleic acid 8-dioxygenation and 8-hydroperoxide isomerization), we found that PpoC apparently only harbours a functional haem peroxidase/dioxygenase domain. Consequently, we observed that PpoC catalyses mainly the dioxygenation of linoleic acid (18:2Δ9Z,12Z), yielding 10-HPODE (10-hydroperoxyoctadecadienoic acid). No isomerase activity was detected. Additionally, 10-HPODE was converted at lower rates into 10-KODE (10-keto-octadecadienoic acid) and 10-HODE (10-hydroxyoctadecadienoic acid). In parallel, decomposition of 10-HPODE into 10-ODA (10-octadecynoic acid) and volatile C-8 alcohols that are, among other things, responsible for the characteristic mushroom flavour. Besides these principle differences we also found that PpoA and PpoC can convert 8-HPODE and 10-HPODE into the respective epoxy alcohols: 12,13-epoxy-8-HOME (where HOME is hydroxyoctadecenoic acid) and 12,13-epoxy-10-HOME. By using site-directed mutagenesis we demonstrated that both enzymes share a similar mechanism for the oxidation of 18:2Δ9Z,12Z; they both use a conserved tyrosine residue for catalysis and the directed oxygenation at the C-8 and C-10 is most likely controlled by conserved valine/leucine residues in the dioxygenase domain.

scholarly journals Mutation of the N-Terminal Region of Chikungunya Virus Capsid Protein: Implications for Vaccine Design

mBio ◽  
2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Adam Taylor ◽  
Xiang Liu ◽  
Ali Zaid ◽  
Lucas Y. H. Goh ◽  
Jody Hobson-Peters ◽  
...  
Keyword(s):  
Host Cell ◽  
Capsid Protein ◽  
Chikungunya Virus ◽  
Fluorescent Protein ◽  
Nuclear Translocation ◽  
Vaccine Design ◽  
Terminal Region ◽  
Site Directed Mutagenesis ◽  
Nucleolar Localization ◽  
Localization Sequence

ABSTRACTMosquito-transmitted chikungunya virus (CHIKV) is an arthritogenic alphavirus of theTogaviridaefamily responsible for frequent outbreaks of arthritic disease in humans. Capsid protein, a structural protein encoded by the CHIKV RNA genome, is able to translocate to the host cell nucleolus. In encephalitic alphaviruses, nuclear translocation induces host cell transcriptional shutoff; however, the role of capsid protein nucleolar localization in arthritogenic alphaviruses remains unclear. Using recombinant enhanced green fluorescent protein (EGFP)-tagged expression constructs and CHIKV infectious clones, we describe a nucleolar localization sequence (NoLS) in the N-terminal region of capsid protein, previously uncharacterized in CHIKV. Mutation of the NoLS by site-directed mutagenesis reduced efficiency of nuclear import of CHIKV capsid protein. In the virus, mutation of the capsid protein NoLS (CHIKV-NoLS) attenuated replication in mammalian and mosquito cells, producing a small-plaque phenotype. Attenuation of CHIKV-NoLS is likely due to disruption of the viral replication cycle downstream of viral RNA synthesis. In mice, CHIKV-NoLS infection caused no disease signs compared to wild-type CHIKV (CHIKV-WT)-infected mice; lack of disease signs correlated with significantly reduced viremia and decreased expression of proinflammatory factors. Mice immunized with CHIKV-NoLS, challenged with CHIKV-WT at 30 days postimmunization, develop no disease signs and no detectable viremia. Serum from CHIKV-NoLS-immunized mice is able to efficiently neutralize CHIKV infectionin vitro. Additionally, CHIKV-NoLS-immunized mice challenged with the related alphavirus Ross River virus showed reduced early and peak viremia postchallenge, indicating a cross-protective effect. The high degree of CHIKV-NoLS attenuation may improve CHIKV antiviral and rational vaccine design.IMPORTANCECHIKV is a mosquito-borne pathogen capable of causing explosive epidemics of incapacitating joint pain affecting millions of people. After a series of major outbreaks over the last 10 years, CHIKV and its mosquito vectors have been able to expand their range extensively, now making CHIKV a human pathogen of global importance. With no licensed vaccine or antiviral therapy for the treatment of CHIKV disease, there is a growing need to understand the molecular determinants of viral pathogenesis. These studies identify a previously uncharacterized nucleolar localization sequence (NoLS) in CHIKV capsid protein, begin a functional analysis of site-directed mutants of the capsid protein NoLS, and examine the effect of the NoLS mutation on CHIKV pathogenesisin vivoand its potential to influence CHIKV vaccine design. A better understanding of the pathobiology of CHIKV disease will aid the development of effective therapeutic strategies.

scholarly journals Linoleic acid-derived 13-hydroxyoctadecadienoic acid is absorbed and incorporated into rat tissues

2020 ◽  
pp. 158870
Author(s):  
Zhichao Zhang ◽  
Shiva Emami ◽  
Marie Hennebelle ◽  
Rhianna K. Morgan ◽  
Larry A. Lerno ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Rat Tissues ◽  
Hydroxyoctadecadienoic Acid

A new conjugated linoleic acid isomer, 7 trans, 9 cis-octadecadienoic acid, in cow milk, cheese, beef and human milk and adipose tissue

Lipids ◽  
1998 ◽  
Vol 33 (8) ◽  
pp. 803-809 ◽  
Author(s):  
Martin P. Yurawecz ◽  
John A. G. Roach ◽  
Najibullah Sehat ◽  
Magdi M. Mossoba ◽  
John K. G. Kramer ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Linoleic Acid ◽  
Human Milk ◽  
Conjugated Linoleic Acid ◽  
Octadecadienoic Acid ◽  
Cow Milk ◽  
Conjugated Linoleic Acid Isomer ◽  
Linoleic Acid Isomer

scholarly journals In silico characterization of linoleic acid biotransformation to rumenic acid in food derived Lactobacillus plantarum YW11

2020 ◽  
Author(s):  
Tariq Aziz ◽  
Abid Sarwar ◽  
Muhammad Fahim ◽  
Sam Al Dalali ◽  
Zia Ud Din ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Lactobacillus Plantarum ◽  
In Silico ◽  
Octadecadienoic Acid ◽  
Scale Up ◽  
Octadecenoic Acid ◽  
Acid Ethyl Ester ◽  
Dependent Manner ◽  
In Silico Characterization

Lactobacillus plantarum YW11 capability to convert linoleic acid into conjugated linoleic acid and other metabolites was studied in a dose-dependent manner by supplementing LA at different concentrations. L. plantarum YW11 displayed a uniform distinctive growth curve of CLA and other metabolites at concentrations of LA ranging from 1% (w/v) to 10% (w/v), with slightly increased growth at higher LA concentrations. The biotransformation capability of L. plantarum YW11 evaluated by GC-MS revealed a total of one CLA isomer, i.e. 9-cis,11-trans-octadecadienoic acid, also known as the rumenic acid (RA), one linoleic acid isomer (linoelaidic acid), and LA metabolites: (E)-9-octadecenoic acid ethyl ester, trans, trans-9,12-octadecadienoic acid, propyl ester and stearic acid. All the metabolites of linoleic acid were produced from 1 to 10% LA supplemented MRS media, while surprisingly the only conjugated linoleic acid compound was produced at 10% LA. To assess the presence of putative enzymes, responsible for conversion of LA into CLA, in silico characterization was carried out. The in silico characterization revealed presence of four enzymes (10-linoleic acid hydratase, linoleate isomerase, acetoacetate decarboxylase and dehydrogenase) that may be involved in the production of CLA (rumenic acid) and LA isomers. The biotransformation ability of L. plantarum YW11 to convert LA into RA has great prospects for biotechnological and industrial implications that could be exploited in the future scale-up experiments.

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