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991.
Scorpio A Blank TE Day WA Chabot DJ 《Cellular and molecular life sciences : CMLS》2006,63(19-20):2237-2248
Anthrax has been a major cause of death in grazing animals and an occasional cause of death in humans for thousands of years. Since the late 1800s there has been an exceptional international history of anthrax vaccine development. Due to animal vaccinations, the rate of infection has dropped dramatically. Anthrax vaccines have progressed from uncharacterized whole-cell vaccines in 1881, to pXO2-negative spores in the 1930s, to culture filtrates absorbed to aluminum hydroxide in 1970, and likely to recombinant protective antigen in the near future. Each of these refinements has increased safety without significant loss of efficacy. The threat of genetically engineered, antibiotic and vaccine resistant strains of Bacillus anthracis is fueling hypothesis-driven research and global techniques--including genomics, proteomics and transposon site hybridization--to facilitate the discovery of novel vaccine targets. This review highlights historical achievements and new developments in anthrax vaccine research. 相似文献
992.
Structural and biological aspects of carotenoid cleavage 总被引:1,自引:0,他引:1
Apo-carotenoid compounds such as retinol (vitamin A) are involved in a variety of cellular processes and are found in all kingdoms of life. Instead of being synthesized from small precursors, they are commonly produced by oxidative cleavage and subsequent modification of larger carotenoid compounds. The cleavage reaction is catalyzed by a family of related enzymes, which convert specific substrate double bonds to the corresponding aldehydes or ketones. The individual family members differ in their substrate preference and the position of the cleaved double bond, giving rise to a remarkable number of products starting from a limited number of carotenoid substrate molecules. The recent determination of the structure of a member of this family has provided insight into the reaction mechanism, showing how substrate specificity is achieved. This review will focus on the biochemistry of carotenoid oxygenases and the structural determinants of the cleavage reaction. 相似文献
993.
Wang X Rochon M Lamprokostopoulou A Lünsdorf H Nimtz M Römling U 《Cellular and molecular life sciences : CMLS》2006,63(19-20):2352-2363
Commensal Escherichia coli form biofilms at body temperature by expressing the extracellular matrix components curli fimbriae and cellulose. The role of curli fimbriae and cellulose in the interaction of commensal E. coli with the intestinal epithelial cell line HT-29 was investigated. Expression of curli fimbriae by the typical commensal isolate E. coli TOB1 caused adherence and internalization of the bacteria and triggered IL-8 production in HT-29 cells. In particular, induction of IL-8 production was complex and involved curli-bound flagellin. While cellulose alone had no effect on the interaction of TOB1 with HT-29 cells, co-expression of cellulose with curli fimbriae decreased adherence to, internalization and IL-8 induction of HT-29 cells. Investigation of a panel of commensal isolates showed a partial correlation between expression of curli fimbriae and enhanced internalization and IL-8 production. In addition, a high immunostimulatory flagellin was identified. Thus, the consequences of expression of extracellular matrix components on commensal bacterial-host interactions are complex. 相似文献
994.
Niimura N Arai S Kurihara K Chatake T Tanaka I Bau R 《Cellular and molecular life sciences : CMLS》2006,63(3):285-300
Neutron diffraction provides an experimental method of directly locating hydrogen atoms in proteins, a technique complimentary to ultra-high-resolution [1, 2] X-ray diffraction. Three different types of neutron diffractometers for biological macromolecules have been constructed in Japan, France and the United States, and they have been used to determine the crystal structures of proteins up to resolution limits of 1.5-2.5 A. Results relating to hydrogen positions and hydration patterns in proteins have been obtained from these studies. Examples include the geometrical details of hydrogen bonds, H/D exchange in proteins and oligonucleotides, the role of hydrogen atoms in enzymatic activity and thermostability, and the dynamical behavior of hydration structures, all of which have been extracted from these structural results and reviewed. Other techniques, such as the growth of large single crystals, the preparation of fully deuterated proteins, the use of cryogenic techniques, and a data base of hydrogen and hydration in proteins, will be described. 相似文献
995.
996.
McTaggart SJ 《Cellular and molecular life sciences : CMLS》2006,63(3):255-267
Isoprenoids are synthesized in all living organisms and are incorporated into diverse classes of end-products that participate
in a multitude of cellular processes relating to cell growth, differentiation, cytoskeletal function and vesicle trafficking.
In humans, the non-sterol isoprenoids, farnesyl pyrophosphate and geranylgeranyl-pyrophosphate, are synthesized via the mevalonate
pathway and are covalently added to members of the small G protein superfamily. Isoprenylated proteins have key roles in membrane
attachment and protein functionality, have been shown to have a central role in some cancers and are likely also to be involved
in the pathogenesis and progression of atherosclerosis and Alzheimer disease. This review details current knowledge on the
biosynthesis of isoprenoids, their incorporation into proteins by the process known as prenylation and the complex regulatory
network that controls these proteins. An improved understanding of these processe is likely to lead to the development of
novel therapies that will have important implications for human health and disease.
Received 5 July 2005; received after revision 17 October 2005; accepted 22 October 2005 相似文献
997.
Gereben B Zeöld A Dentice M Salvatore D Bianco AC 《Cellular and molecular life sciences : CMLS》2008,65(4):570-590
The thyroid hormone plays a fundamental role in the development, growth, and metabolic homeostasis in all vertebrates by affecting
the expression of different sets of genes. A group of thioredoxin fold-containing selenoproteins known as deiodinases control
thyroid hormone action by activating or inactivating the precursor molecule thyroxine that is secreted by the thyroid gland.
These pathways ensure regulation of the availability of the biologically active molecule T3, which occurs in a time-and tissue-specific
fashion. In addition, because cells and plasma are in equilibrium and deiodination affects central thyroid hormone regulation,
these local deiodinase-mediated events can also affect systemic thyroid hormone economy, such as in the case of non-thyroidal
illness. Heightened interest in the field has been generated following the discovery that the deiodinases can be a component
in both the Sonic hedgehog signaling pathway and the TGR-5 signaling cascade, a G-protein-coupled receptor for bile acids.
These new mechanisms involved in deiodinase regulation indicate that local thyroid hormone activation and inactivation play
a much broader role than previously thought.
Received 29 August 2007; received after revision 11 October 2007; accepted 16 October 2007 相似文献
998.
Specific protein-protein interactions are essential for cellular functions. Experimentally determined three-dimensional structures
of protein-protein complexes offer the possibility to characterize binding interfaces in terms of size, shape and packing
density. Comparison with crystal-packing interfaces representing nonspecific protein-protein contacts gives insight into how
specific binding differs from nonspecific low-affinity binding. An overview is given on empirical structural rules for specific
protein-protein recognition derived from known complex structures. Although single parameters such as interface size, shape
or surface complementary show clear trends for different interface types, each parameter alone is insufficient to fully distinguish
between specific versus crystal-packing contacts. A combination of interface parameters is, however, well suited to characterize a specific interface.
This knowledge provides us with the essential ingredients that make up a specific protein recognition site. It is also of
great value for the prediction of protein binding sites and for the evaluation of predicted complex structures.
Received 1 October 2007; received after revision 9 November 2007; accepted 9 November 2007 相似文献
999.
Lubelski J Rink R Khusainov R Moll GN Kuipers OP 《Cellular and molecular life sciences : CMLS》2008,65(3):455-476
This review discusses the state-of-the-art in molecular research on the most prominent and widely applied lantibiotic, i.e., nisin. The developments in understanding its complex biosynthesis and mode of action are highlighted. Moreover, novel applications
arising from engineering either nisin itself, or from the construction of totally novel dehydrated and/or lanthionine-containing
peptides with desired bioactivities are described. Several challenges still exist in understanding the immunity system and
the unique multiple reactions occurring on a single substrate molecule, carried out by the dehydratase NisB and the cyclization
enzyme NisC. The recent elucidation of the 3-D structure of NisC forms the exciting beginning of further 3-D-structure determinations
of the other biosynthetic enzymes, transporters and immunity proteins. Advances in achieving in vitro activities of lanthionine-forming enzymes will greatly enhance our understanding of the molecular characteristics of the
biosynthesis process, opening up new avenues for developing unique and novel biocatalytic processes.
Received 9 April 2007; received after revision 31 August 2007; accepted 28 September 2007 相似文献
1000.
Many notions regarding the function, structure and regulation of cholera toxin expression have remained essentially unaltered
in the last 15 years. At the same time, recent findings have generated additional perspectives. For example, the cholera toxin
genes are now known to be carried by a non-lytic bacteriophage, a previously unsuspected condition. Understanding of how the
expression of cholera toxin genes is controlled by the bacterium at the molecular level has advanced significantly and relationships
with cell-density-associated (quorum-sensing) responses have recently been discovered. Regarding the cell intoxication process,
the mode of entry and intracellular transport of cholera toxin are becoming clearer. In the immunological field, the strong
oral immunogenicity of the non-toxic B subunit of cholera toxin (CTB) has been exploited in the development of a now widely
licensed oral cholera vaccine. Additionally, CTB has been shown to induce tolerance against co-administered (linked) foreign
antigens in some autoimmune and allergic diseases.
Received 25 October 2007; accepted 12 December 2007 相似文献