1. The pharmacokinetic profile and protein binding parameters of ceftriaxone were determined in rat, and compared with those of cefotaxime. 2. Plasma concentration-time curves of ceftriaxone and cefotaxime (single i.v. bolus; 100 mg/kg each) were described by a two-compartment, protein-binding model. 3. The corrected VTss (ml/kg) of ceftriaxone was lower than that of cefotaxime. The AUCs of both drugs were similar. The t1/2 beta of the two drugs differed significantly, being 29 min for ceftriaxone and 17 min for cefotaxime. 4. In vivo protein binding constants of both drugs were similar, but the concentrations of protein binding sites differed significantly. The average free fractions in plasma (Fp) of ceftriaxone and cefotaxime were 0.22 and 0.48 respectively. 5. Saturation of the binding site for cefotaxime was estimated to occur at about 30 micrograms/ml in plasma, whereas saturation for ceftriaxone was seen at lower concentrations.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.3109/00498258909043142 | DOI Listing |
FEBS Lett
January 2025
Research Department, Purotech Bio Inc, Yokohama, Japan.
Hepatitis B virus (HBV) infects cells by attaching to heparan sulfate proteoglycans (HSPG) and Na/taurocholate cotransporting polypeptide (NTCP). The endothelial lipase LIPG bridges HSPG and HBV, facilitating HBV attachment. From a randomized peptide expression library, we identified a short sequence binding to LIPG.
View Article and Find Full Text PDFCancer
February 2025
Departmental Unit of Molecular and Genomic Diagnostics, Genomics Core Facility, G-STeP, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy.
Background: To date, 11 DNA polymerase epsilon (POLE) pathogenic variants have been declared "hotspot" mutations. Patients with endometrial cancer (EC) characterized by POLE hotspot mutations (POLEmut) have exceptional survival outcomes. Whereas international guidelines encourage deescalation of adjuvant treatment in early-stage POLEmut EC, data regarding safety in POLEmut patients with unfavorable characteristics are still under investigation.
View Article and Find Full Text PDFProtein Sci
February 2025
Department of Chemistry and Biochemistry, Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA.
Loz1 is a zinc-responsive transcription factor in fission yeast that maintains cellular zinc homeostasis by repressing the expression of genes required for zinc uptake in high zinc conditions. Previous deletion analysis of Loz1 found a region containing two tandem CH zinc-fingers and an upstream "accessory domain" rich in histidine, lysine, and arginine residues to be sufficient for zinc-dependent DNA binding and gene repression. Here we report unexpected biophysical properties of this pair of seemingly classical CH zinc fingers.
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.
View Article and Find Full Text PDFProtein Sci
February 2025
Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois, USA.
We have developed a portfolio of antibody-based modules that can be prefabricated as standalone units and snapped together in plug-and-play fashion to create uniquely powerful multifunctional assemblies. The basic building blocks are derived from multiple pairs of native and modified Fab scaffolds and protein G (PG) variants engineered by phage display to introduce high pair-wise specificity. The variety of possible Fab-PG pairings provides a highly orthogonal system that can be exploited to perform challenging cell biology operations in a straightforward manner.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!