Three circularly permuted variants of Escherichia coli dihydrofolate reductase genes were constructed. Linkers coding tri- and pentapeptides were used to connect the natural 5'- and 3'-terminal ends. Only one variant of circularly permuted protein with tripeptide linker and the cleavage of the peptide bond between 107 and 108 amino acid residues was produced in a good yield. The expressed protein was insoluble in the cells, but at pH 8.0 and higher the isolated protein was soluble. Enzymatic assay and physical studies have shown that permuted dihydrofolate reductase has a destabilized tertiary structure. Only the addition of the natural substrates or inhibitors lead to the protein with the native-like structure and functional activity.
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http://dx.doi.org/10.1093/protein/7.11.1373 | DOI Listing |
Talanta
January 2025
Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, School of Life Sciences, Tianjin University, 92 Weijin Road, Nankai District, Tianjin, 300072, China; Haihe Laboratory of Sustainable Chemical Transformations, Tianjin, 300192, China. Electronic address:
The growing demand for glycolate, fueled by economic development, requires the advancement of production methods. Escherichia coli (E. coli), a preferred host for glycolate production, has undergone extensive metabolic engineering to improve yield.
View Article and Find Full Text PDFSensors (Basel)
December 2024
Central Hospital of Dalian University of Technology, Dalian 116021, China.
Non-small cell lung cancer (NSCLC) is the predominant form of lung cancer and poses a significant public health challenge. Early detection is crucial for improving patient outcomes, with serum biomarkers such as carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCCAg), and cytokeratin fragment 19 (CYFRA 21-1) playing a critical role in early screening and pathological classification of NSCLC. However, due to being mainly based on corresponding antibody binding reactions, existing detection technologies for these serum biomarkers have shortcomings such as complex operations, high false positive rates, and high costs.
View Article and Find Full Text PDFRSC Chem Biol
December 2024
School of Chemistry and Chemical Engineering, University of South China Hengyang 421001 China +86-743-8578079.
Androglobin (Adgb) was discovered as the fifth mammalian globin, but its structure and function remain elusive. In this study, the heme-binding globin domain of Adgb was expressed and its interaction with calmodulin (CaM) was investigated. The protein structure of Adgb and its complex with CaM were predicted using AlphaFold3 and HDOCK.
View Article and Find Full Text PDFAntioxidants (Basel)
November 2024
College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Republic of Korea.
MsrB1 is a thiol-dependent enzyme that reduces protein methionine--sulfoxide and regulates inflammatory response in macrophages. Therefore, MsrB1 could be a promising therapeutic target for the control of inflammation. To identify MsrB1 inhibitors, we construct a redox protein-based fluorescence biosensor composed of MsrB1, a circularly permutated fluorescent protein, and the thioredoxin1 in a single polypeptide chain.
View Article and Find Full Text PDFJ Phys Chem B
November 2024
Cellular Protein Chemistry, Bijvoet Centre for Biomolecular Research, Faculty of Science, Utrecht University, Utrecht 3584 CH, The Netherlands.
Weak nonspecific interactions between biomacromolecules determine the cytoplasmic organization. Despite their importance, it is challenging to determine these interactions in the intracellular dense and heterogeneous mixture of biomacromolecules. Here, we develop a method to indicate electrostatic and hydrophobic associative interactions and map these interactions.
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