The rate of radiation damage to macromolecular crystals at both room temperature and 100 K has previously been shown to be reduced by the use of certain radical scavengers. Here the effects of sodium nitrate, an electron scavenger, are investigated at 100 K. For sodium nitrate at a concentration of 0.5 M in chicken egg-white lysozyme crystals, the dose tolerance is increased by a factor of two as judged from the global damage parameters, and no specific structural damage to the disulfide bonds is seen until the dose is greatly in excess (more than a factor of five) of the value at which damage appears in electron density maps derived from a scavenger-free crystal. In the electron density maps, ordered nitrate ions adjacent to the disulfide bonds are seen to lose an O atom, and appear to protect the disulfide bonds. In addition, results reinforcing previous reports on the effectiveness of ascorbate are presented. The mechanisms of action of both scavengers in the crystalline environment are elucidated.
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http://dx.doi.org/10.1107/S0909049511007163 | DOI Listing |
Mater Today Bio
February 2025
Basic Research Key Laboratory of General Surgery for Digital Medicine, Affiliated Hospital of Hebei University, Baoding, 071000, China.
Achilles tendon is a motor organ that is prone to tissue adhesion during its repair process after rupture. Therefore, developing motion-responsive and anti-adhesive biomaterials is an important need for the repair of Achilles tendon rupture. Here, we report an injectable lubricative hydrogel (ILH) based on hydration lubrication mechanism, which is also motion-responsive based on sol-gel reversible transmission.
View Article and Find Full Text PDFAnal Methods
January 2025
College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, P.R. China.
Platelet factor 4 (PF4), a specific protein primarily found in megakaryocytes and platelet α-granules, plays an essential role in the coagulation process. It carries a high positive charge and thus has a unique ability to readily form complexes with negatively charged heparin. This interaction between PF4 and heparin plays a crucial role in platelet aggregation and thrombosis, resulting in heparin-induced thrombocytopenia (HIT).
View Article and Find Full Text PDFBiotechnol Prog
January 2025
Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Okayama, Japan.
The production of disulfide-containing recombinant proteins often requires refolding of inclusion bodies before purification. A pre-refolding purification step is crucial for effective refolding because impurities in the inclusion bodies interfere with refolding and subsequent purification. This study presents a new pre-refolding procedure using a reversible S-cationization technique for protein solubilization and purification by reversed-phase high performance liquid chromatography.
View Article and Find Full Text PDFJ Biol Chem
January 2025
Departments of Neurology, University of Michigan, Ann Arbor, MI 48109; Departments of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109; Neurology Service, VA Ann Arbor Healthcare System, Department of Veterans Affairs, Ann Arbor, MI 48105. Electronic address:
Stereotyped mutations in NOTCH3 drive CADASIL, the leading inherited cause of stroke and vascular dementia. The vast majority of these mutations result in alterations in the number of cysteines in the gene product. However, non-cysteine altering pathogenic mutations have also been identified, making it challenging to discriminate pathogenic from benign NOTCH3 sequence variants.
View Article and Find Full Text PDFProtein Expr Purif
January 2025
Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai, Miyagi 981-8558, Japan. Electronic address:
Dectin-1 (CLEC7A), a C-type lectin-like receptor that recognizes β-1,3 glucans, has a key role in the innate immune system. While the lectin domain of mouse Dectin-1 has been solubilized and refolded from inclusion bodies in Escherichia coli, similar refolding of the human Dectin-1 lectin domain is hindered by the formation of misfolded multimers with aberrant intermolecular disulfide bonds. The aim of this study was to develop a method for the large-scale production of the human Dectin-1 lectin domain.
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