We evaluate the ability of hexahistidine (His6) tags on peptide and protein substrates to recruit deoxyribozymes for modifying those substrates. For two different deoxyribozymes, one that creates tyrosine-RNA nucleopeptides and another that phosphorylates tyrosine side chains, we find substantial improvements in yield, kobs, and Km for peptide substrates due to recruiting by His6/Cu(2+). However, the recruiting benefits of the histidine tag are not observed for larger protein substrates, likely because the tested deoxyribozymes either cannot access the target peptide segments or cannot function when these segments are presented in a structured protein context.
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http://dx.doi.org/10.1039/c6ob00716c | DOI Listing |
Clin Chem Lab Med
January 2025
Deparment of Laboratory Medicine, 16268 La Paz University Hospital, Madrid, Spain.
Objectives: Cardiac biomarkers are useful for the diagnostic and prognostic assessment of myocardial injury (MI) and heart failure. By measuring specific proteins released into the bloodstream during heart stress or damage, these biomarkers help clinicians detect the presence and extent of heart injury and tailor appropriate treatment plans. This study aims to provide robust biological variation (BV) data for cardiac biomarkers in athletes, specifically focusing on those applied to detect or exclude MI, such as myoglobin, creatine kinase-myocardial band (CK-MB) and cardiac troponins (cTn), and those related to heart failure and cardiac dysfunction, brain natriuretic peptide (BNP) and N-terminal brain natriuretic pro-peptide (NT-proBNP).
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Nanjing University, School of Chemistry and Chemical Engineering, No. 163 Xianlin Road, 210023, Nanjing, CHINA.
Hydroxylation, an extensive post-translational modification on proline, is critical for the modulation of protein structures, further dominating their functions in life systems. However, current mass spectrometry-based identification, could hardly distinguish hydroxylation from neighboring oxidation due to the same mass shifts, as well as challenges posed by low abundance and exogenous oxidation during sample preparation. To address these, an engineered nanopore was designed, capable of discriminating single hydroxyl group, to achieve the identification of proline hydroxylation on individual native peptides directly in the mixture.
View Article and Find Full Text PDFJ Pept Sci
March 2025
Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense, Denmark.
Fluorescent probes are widely used in cellular imaging and disease diagnosis. Acting as substitute carriers, fluorescent probes can also be used to help transport drugs within cells. In this study, commonly used fluorophores, TAMRA (5-carboxytetramethylrhodamine), PBA (1-pyrenebutyric acid), NBD (nitrobenzoxadiazole), OG (Oregon Green), and CF (5-carboxyfluorescein) were conjugated with the dipeptide β-Ala-Lys, the peptide moiety of the well-established peptide transporter substrate β-Ala-Lys(AMCA) (AMCA: 7-amino-4-methyl-coumarin-3-acetic acid) by modifying it with respect to side-chain length and functional end groups.
View Article and Find Full Text PDFBiotechnol J
January 2025
Department of Biological Sciences, KAIST, Daejeon, Republic of Korea.
Increasing demand for adeno-associated virus (AAV) used in gene therapy highlights the need to enhance AAV production. When intracellular AAV2 and extracellular AAV9 were produced in HEK293T cells using the triple transfection method, apoptosis occurred during the AAV production. To mitigate apoptosis induced by AAV production, the pro-apoptotic BAX/BAK1 genes were knocked out in HEK293T cells.
View Article and Find Full Text PDFProtein Sci
February 2025
Department of Physics, University of Washington, Seattle, Washington, USA.
Proteins' flexibility is a feature in communicating changes in cell signaling instigated by binding with secondary messengers, such as calcium ions, associated with the coordination of muscle contraction, neurotransmitter release, and gene expression. When binding with the disordered parts of a protein, calcium ions must balance their charge states with the shape of calcium-binding proteins and their versatile pool of partners depending on the circumstances they transmit. Accurately determining the ionic charges of those ions is essential for understanding their role in such processes.
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