We evaluate the impact of carbamylation of the primary amines of the side-chains of Lys and the N-termini on the fragmentation of intact protein ions and the chromatographic properties of a mixture of E. coli ribosomal proteins. The fragmentation patterns of the six unmodified and carbamylated proteins obtained by higher energy collision dissociation (HCD) and ultraviolet photodissociation (UVPD) were compared. Carbamylation significantly reduced the total number of protons retained by the protein owing to the conversion of basic primary amines to non-basic carbamates. Carbamylation caused a significant negative impact on fragmentation of the protein by HCD (i.e., reduced sequence coverage and fewer diagnostic fragment ions) consistent with the mobile proton model, which correlates peptide fragmentation with charge distribution and the opportunity for charge-directed pathways. In addition, fragmentation was enhanced near the N- and C-termini upon HCD of carbamylated proteins. For LCMS/MS analysis of E. coli ribosomal proteins, the retention times increased by 16 min on average upon carbamylation, an outcome attributed to the increased hydrophobicity of the proteins after carbamylation. As noted for both the six model proteins and the ribosomal proteins, carbamylation had relatively little impact on the distribution or types of fragment ions product by UVPD, supporting the proposition that the mechanism of UVPD for intact proteins does not reflect the mobile proton model. Graphical Abstract ᅟ.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5624212 | PMC |
http://dx.doi.org/10.1007/s13361-017-1648-5 | DOI Listing |
J Integr Neurosci
January 2025
Neuroscience Department, University of Connecticut Health, School of Medicine, Institute for Systems Genomics, Farmington, CT 06030, USA.
Background: In neuroscience, Ca imaging is a prevalent technique used to infer neuronal electrical activity, often relying on optical signals recorded at low sampling rates (3 to 30 Hz) across multiple neurons simultaneously. This study investigated whether increasing the sampling rate preserves critical information that may be missed at slower acquisition speeds.
Methods: Primary neuronal cultures were prepared from the cortex of newborn pups.
Molecules
January 2025
Department of Organic Chemistry and Technology, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, Műegyetem rkp. 3, 1111 Budapest, Hungary.
Butyl phenyl--phosphinate that is not available commercially was prepared from phenyl--phosphinic acid by three methods: by alkylating esterification (i), by microwave-assisted direct esterification (ii), and unexpectedly, by thermal esterification (iii). Considering the green aspects, selectivity and scalability, the thermal variation seemed to be optimal. However, there was need for prolonged heating.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Department of Pediatrics, National Jewish Health, Denver, CO 80206, USA.
The cystic fibrosis transmembrane conductance regulator (CFTR) is an anion channel that is dysfunctional in individuals with cystic fibrosis (CF). The permeability of CFTR can be experimentally manipulated though different mechanisms, including activation via inducing the phosphorylation of residues in the regulatory domain as well as altering the gating/open probability of the channel. Phosphorylation/activation of the channel is achieved by exposure to compounds that increase intracellular cAMP, with forskolin and IBMX commonly used for this purpose.
View Article and Find Full Text PDFBiomolecules
December 2024
Laboratory of Vascular Pathology and Diabetes, IIS-Fundación Jiménez Díaz, 28040 Madrid, Spain.
Background: Plasma metabolites could be suitable as predictive biomarkers for cardiovascular pathologies or death, thereby improving the prediction of protein biomarkers. The release of acylcarnitines may be altered after coronary artery disease (CAD) in subjects with recurrent clinical outcomes, and this could be used as a prognosis tool.
Methods: Patients with stable coronary artery disease (SCAD) who had suffered an acute coronary syndrome 6-9 months before were followed for up to 4.
BMC Anesthesiol
January 2025
Department of Anesthesiology, The Third People's Hospital of Bengbu, 38 Shengli Middle Road, Bengbu, 233000, China.
Background: The use of a fluid co-load has been shown to enhance hemodynamic stability and diminish the occurrence of hypotension after spinal anesthesia when paired with prophylactic norepinephrine. This research aimed to identify the effective dosages (ED and ED) of prophylactic norepinephrine boluses, in conjunction with a crystalloid co-load, for the prevention of hypotension after spinal anesthesia in cesarean delivery patients.
Methods: Patients were administered crystalloid co-loads at a dosage of 10 mL/kg, in addition to preventive norepinephrine dosages direct following spinal anesthesia administration.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!