PubMed · 14914541
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
E ERNST, J BALOG, J TIGYI, A SEBES. 1951. [Volume decrease and crystallization in muscle and myosin].. https://pubmed.ncbi.nlm.nih.gov/14914541/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
The X-ray crystal structure of uncomplexed Escherichia coli RecA protein has been determined in three new crystal forms at resolutions of 1.9 A, 2.0 A, and 2.6 A. The RecA protein used for this study contains the extra residues Gly-Ser-His-Met at the N terminus, but retains normal ssDNA-dependent ATPase and coprotease activities. In all three crystals, RecA is packed in a right-handed helical filament with a pitch of approximately 74 A. These RecA filaments are compressed relative to the original crystal structure of RecA, which has a helical pitch of 82.7 A. In the structures of the compressed RecA filament, the monomer-monomer interface and the core domain are essentially the same as in the RecA structure with the 83 A pitch. The change in helical pitch is accommodated by a small movement of the N-terminal domain, which is reoriented to preserve the contacts it makes at the monomer-monomer interface. The new crystal structures show significant variation in the orientation and conformation of the C-terminal domain, as well as in the inter-filament packing interactions. In crystal form 2, a calcium ion is bound closely to a beta-hairpin of the C-terminal domain and to Asp38 of a neighboring filament, and residues 329-331 of the C-terminal tail become ordered to contact a neighboring filament. In crystal forms 3 and 4, a sulfate ion or a phosphate anion is bound to the same site on RecA as the beta-phosphate group of ADP, causing an opening of the P-loop. Altogether, the structures show the conformational variability of RecA protein in the crystalline state, providing insight into many aspects of RecA function.
A process for the value addition of solid waste from two-phase olive oil extraction or "alperujo" that includes a hydrothermal treatment has been suggested. In this treatment an autohydrolysis process occurs and the solid olive byproduct is partially solubilized. From this water-soluble fraction can be obtained besides the antioxidant hydroxytyrosol several other compounds of high added value. In this paper three different samples of alperujo were characterized and subjected to a hydrothermal treatment with and without acid catalyst. The main soluble compounds after the hydrolysis were represented by monosaccharides xylose, arabinose, and glucose; oligosaccharides, mannitol and products of sugar destruction. Oligosaccharides were separated by size exclusion chromatography. It was possible to get highly purified mannitol by applying a simple purification method.
We report a reversible liquid-solid transition upon heating of a simple solution composed of a-cyclodextrine (alpha CD), water, and 4-methylpyridine. These solutions are homogeneous and transparent at ambient temperature and solidify when heated to temperatures between 45 degrees and 75 degrees. Quasielastic and elastic neutron scattering show that molecular motions are slowed down in the solid and that crystalline order is established. The solution "freezes on heating." This process is fully reversible, on cooling the solid melts. A rearrangement of hydrogen bonds is postulated to be responsible for the observed phenomenon.