A novel nicotinamide adenine dinucleotide (NADH) oxidase from Streptococcus mutans ATCC 25175 (SmNox) was cloned and overexpressed in Escherichia coli BL21 (DE3). Sequence analysis revealed an open reading frame of 1374bp, capable of encoding a polypeptide of 457 amino acid residues. The molecular mass of the purified SmNox was estimated to be ∼49.9kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified SmNox had the highest specific activity of 281.2U·mg at optimal pH and temperature of 7.0 and 35°C, with a K of 57.7μM and a V of 154.3U·mg. The good stability at room temperature was observed. Homology modeling and substrate docking were performed to evaluate the catalytic characteristics. The results indicated that Nicotinamide ring of NADH extends vertically toward to re-face of coenzyme (FAD), and the specific conformation of NADH suggested that the charges transfer in SmNox complex could be easier than in its homologous enzyme (LbNox) under alkaline environment. The characterization of the SmNox indicated it has potential in industrial regeneration of coenzyme NAD for coupling with dehydrogenases.
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http://dx.doi.org/10.1016/j.ijbiomac.2018.03.016 | DOI Listing |
J Struct Biol
January 2025
Postgraduate Program in Industrial Biotechnology, Tiradentes University, Aracaju, Sergipe, Brazil; Department of Morphology, Federal University of Sergipe, São Cristóvão, Sergipe, Brazil. Electronic address:
Cry proteins, commonly found in gram-positive soil bacteria, are used worldwide as aerial sprays or in transgenic plants for controlling crop pest populations and as insect vectors. Via PCR analysis, a spore producing soil isolate (BV5) was speculated to encode a Cry gene. Partial nucleotide sequence of the amplified PCR fragment showed homology with the Cry8 genes present in GenBank.
View Article and Find Full Text PDFMetal-organic frameworks (MOFs) are porous, crystalline materials with high surface area, adjustable porosity, and structural tunability, making them ideal for diverse applications. However, traditional experimental and computational methods have limited scalability and interpretability, hindering effective exploration of MOF structure-property relationships. To address these challenges, we introduce, for the first time, a category-specific topological learning (CSTL), which combines algebraic topology with chemical insights for robust property prediction.
View Article and Find Full Text PDFNovel multiplexed spatial proteomics imaging platforms expose the spatial architecture of cells in the tumor microenvironment (TME). The diverse cell population in the TME, including its spatial context, has been shown to have important clinical implications, correlating with disease prognosis and treatment response. The accelerating implementation of spatial proteomic technologies motivates new statistical models to test if cell-level images associate with patient-level endpoints.
View Article and Find Full Text PDFCommun Biol
January 2025
Department of Medicine, Universite de Montreal, Montreal, QC, Canada.
Severe COVID-19 can trigger a cytokine storm, leading to acute respiratory distress syndrome (ARDS) with similarities to superantigen-induced toxic shock syndrome. An outstanding question is whether SARS-CoV-2 protein sequences can directly induce inflammatory responses. In this study, we identify a region in the SARS-CoV-2 S2 spike protein with sequence homology to bacterial super-antigens (termed P3).
View Article and Find Full Text PDFiScience
December 2024
Ningxia Key Laboratory of Clinical and Pathogenic Microbiology, Institute of Medical Sciences, General Hospital of Ningxia Medical University, Yinchuan, Ningxia 750004, China.
The global prevalence of ST11 hypervirulent carbapenem-resistant (hv-CRKP) isolates has been increasingly documented, yet genomic characterization of this clone remains insufficiently explored. Here, we report a clinical ST11-KL25 hv-CRKP strain (KP156) that exhibited resistance to multiple antibiotics and demonstrated hypervirulence in a mouse infection model. Whole-genome sequencing revealed that KP156 harbored one virulence plasmid (pKP156-Vir) and two resistance plasmids (pKP156-KPC and pKP156-tetA).
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