K-edge anomalous SAXS intensity was measured from a small, dimeric, partly unstructured protein segment of myosin X by using cupric ions bound to its C-terminal polyhistidine tags. Energy-dependent anomalous SAXS can provide key location-specific information about metal-labeled protein structures in solution that cannot be obtained from routine SAXS analysis. However, anomalous SAXS is seldom used for protein research due to practical difficulties, such as a lack of generic multivalent metal-binding tags and the challenges of measuring weak anomalous signal at the metal absorption edge. This pilot feasibility study suggests that weak K-edge anomalous SAXS signal can be obtained from transition metals bound to terminally located histidine tags of small proteins. The measured anomalous signal can provide information about the distribution of all metal-protein distances in the complex. Such an anomalous SAXS signal can assist in the modeling and validation of structured or unstructured proteins in solution and may potentially become a new addition to the repertoire of techniques in integrative structural biology.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1107/S205979832101247X | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
RAFT Dispersion Polymerization of 2-Hydroxyethyl Methacrylate in Non-polar Media.
Macromolecules
December 2024
Dainton Building, Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K.
We report the reversible addition-fragmentation chain transfer (RAFT) dispersion polymerization of 2-hydroxyethyl methacrylate (HEMA) in -dodecane using a poly(lauryl methacrylate) (PLMA) precursor at 90 °C. This formulation is an example of polymerization-induced self-assembly (PISA), which leads to the formation of a colloidal dispersion of spherical PLMA-PHEMA nanoparticles at 10-20% w/w solids. PISA syntheses involving polar monomers in non-polar media have been previously reported but this particular system offers some unexpected and interesting challenges in terms of both synthesis and characterization.
View Article and Find Full Text PDFA genetically encoded anomalous SAXS ruler to probe the dimensions of intrinsically disordered proteins.
Proc Natl Acad Sci U S A
December 2024
Biocenter, Johannes Gutenberg University Mainz, Mainz 55128, Germany.
Intrinsically disordered proteins (IDPs) adopt ensembles of rapidly fluctuating heterogeneous conformations, influencing their binding capabilities and supramolecular transitions. The primary conformational descriptors for understanding IDP ensembles-the radius of gyration (), measured by small-angle X-ray scattering (SAXS), and the root mean square (rms) end-to-end distance (), probed by fluorescent resonance energy transfer (FRET)-are often reported to produce inconsistent results regarding IDP expansion as a function of denaturant concentration in the buffer. This ongoing debate surrounding the FRET-SAXS discrepancy raises questions about the overall reliability of either method for quantitatively studying IDP properties.
View Article and Find Full Text PDFMetal fluorides-multi-functional tools for the study of phosphoryl transfer enzymes, a practical guide.
Structure
October 2024
European Molecular Biology Laboratory, 71 avenue des Martyrs, CS 90181, 38042 Grenoble, France. Electronic address:
Enzymes facilitating the transfer of phosphate groups constitute the most extensive protein families across all kingdoms of life. They make up approximately 10% of the proteins found in the human genome. Understanding the mechanisms by which enzymes catalyze these reactions is essential in characterizing the processes they regulate.
View Article and Find Full Text PDFUnimer suppression enables supersaturated homopolymer swollen micelles with long-term stability after glassy entrapment.
Soft Matter
March 2024
Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208.
Micelle sizes are critical for a range of applications where the simple ability to adjust and lock in specific stable sizes has remained largely elusive. While micelle swelling agents are well-known, their dynamic re-equilibration in solution implies limited stability. Here, a non-equilibrium processing sequence is studied where supersaturated homopolymer swelling is combined with glassy-core ("persistent") micelles.
View Article and Find Full Text PDFH-bond network, interfacial tension and chain melting temperature govern phospholipid self-assembly in ionic liquids.
J Colloid Interface Sci
March 2024
School of Chemistry and University of Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia. Electronic address:
Hypothesis: The self-assembly structures and phase behaviour of phospholipids in protic ionic liquids (ILs) depend on intermolecular forces that can be controlled through changes in the size, polarity, and H-bond capacity of the solvent.
Experiments: The structure and temperature stability of the self-assembled phases formed by four phospholipids in three ILs was determined by a combination of small- and wide-angle X-ray scattering (SAXS and WAXS) and small-angle neutron scattering (SANS). The phospholipids have identical phosphocholine head groups but different alkyl tail lengths and saturations (DOPC, POPC, DPPC and DSPC), while the ILs' amphiphilicity, H-bond network density and polarity are varied between propylammonium nitrate (PAN) to ethylammonium nitrate (EAN) to ethanolammonium nitrate (EtAN).
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!