Recombinant human 5-lipoxygenase (arachidonate:oxygen 5-oxidoreductase, EC 1.13.11.34) was expressed in Escherichia coli. In incubations of E. coli supernatants with arachidonic acid, 5-hydroxy-7,9,11,14-eicosatetraenoic acid and leukotriene A4 were formed, while incubation with 8,11,14-eicosatrienoic acid gave 8-hydroxy-9,11,14-eicosatrienoic acid. Six conserved histidine residues in 5-lipoxygenase were subjected to site-directed mutagenesis. Exchanges of His-367, -372, or -551 gave mutants for which no enzyme activities were detectable. On the other hand, exchanges of His-362, -390, or -399 gave mutants that were enzymatically active, but less so than the nonmutated control. For two of these (exchanges of His-390 or -399), the activities of the mutants were dependent on the expression temperature. Thus, the histidines in the first group (His-367, -372, -551) were crucial for 5-lipoxygenase activity, possibly because of a function of these residues as metal ligands. Mutagenesis aimed at two other conserved elements in 5-lipoxygenase, Gln-558 and the C terminus, gave mutated proteins with only a small residual activity (substitution of Gln-558), or with no detectable activity (deletion of six C-terminal amino acids), indicating that these regions are important for the function of 5-lipoxygenase.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC48263 | PMC |
| http://dx.doi.org/10.1073/pnas.89.2.485 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The ETS domain-containing hematopoietic transcription factor PU.1 mediates the induction of arachidonate 5-lipoxygenase by multi-walled carbon nanotubes in macrophages in vitro.
Arch Toxicol
December 2024
Receptor Biology Laboratory, Toxicology and Molecular Biology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, 26505, USA.
Exposure to fibrogenic multi-walled carbon nanotubes (MWCNTs) induces the production of proinflammatory lipid mediators (LMs) in myeloid cells to instigate inflammation. The molecular underpinnings of LM production in nanotoxicity remain unclear. Here we report that PU.
View Article and Find Full Text PDFAn Experimental Study to Evaluate the Antidepressant Effect of Zileuton and Aqueous Extract of Phyllanthus emblica in Unpredictable Chronic Mild Stress-Induced Depression in Albino Mice.
Cureus
November 2024
Pharmacology and Therapeutics, Seth Gordhandas Sunderdas Medical College and King Edward Memorial (KEM) Hospital, Mumbai, IND.
Introduction: Oxidative stress and proinflammatory signaling in the brain have been found to have a significant role in the pathogenesis of depression. Therefore, drugs that reduce oxidative stress and neuroinflammation may be helpful in depression as monotherapy or as an adjunct to conventional antidepressants. Zileuton, a 5-lipoxygenase inhibitor, has been identified as a putative antidepressant in an in vitro study.
View Article and Find Full Text PDFDiscovery of Sporachelins by Genome Mining of a Strain.
J Nat Prod
December 2024
State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China.
Myxochelins are a group of catecholate siderophores encoded by biosynthetic gene clusters (BGCs). They are mainly produced by myxobacteria and display a wide variety of bioactivities. Herein, we report a group of new myxochelins produced not by a myxobacterial strain but by an actinobacteria strain, sp.
View Article and Find Full Text PDFPolygenic and transcriptional risk scores identify chronic obstructive pulmonary disease subtypes in the COPDGene and ECLIPSE cohort studies.
EBioMedicine
December 2024
Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA, 02115, USA; Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA, 02115, USA; Harvard Medical School, Boston, MA, 02115, USA. Electronic address:
Background: Genetic variants and gene expression predict risk of chronic obstructive pulmonary disease (COPD), but their effect on COPD heterogeneity is unclear. We aimed to define high-risk COPD subtypes using genetics (polygenic risk score, PRS) and blood gene expression (transcriptional risk score, TRS) and assess differences in clinical and molecular characteristics.
Methods: We defined high-risk groups based on PRS and TRS quantiles by maximising differences in protein biomarkers in a COPDGene training set and identified these groups in COPDGene and ECLIPSE test sets.
Homocysteine aggravates intestinal inflammation through promotion of 5-LOX and COX-2 in IBD.
Eur J Med Res
November 2024
Department of Gastroenterology, The First Affiliated Hospital of Anhui Medical University, No. 218 JiXi Road, Hefei, 230022, Anhui, People's Republic of China.
Background: Homocysteine (Hcy) is a pro-inflammatory molecule that has the potential to induce oxidative damage to cells and stimulate the release of inflammatory mediators. Hcy has been observed to enhance the production of inflammatory agents in vascular endothelial cells. However, the impact of Hcy on intestinal mucosal inflammation remains largely unexplored.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!