Date: Sat, 3 Nov 2001 12:29:44 -0800 (PST) From: Mike Reynolds <aquaviva11-AT-yahoo.com> Subject: B. anthracis The white beast clamped its claws into Shenfa. The blue dragon draped its tail over Xin and Fang. The dark turtle pulled in its head at Nu and Xu. The red bird stirred up its wings in Zhu and Zhang. [Chenggong sui, Tiandi fu] The evolutionary origin of the pathogen seems to be Kruger National Park, South Africa. Of the two major strains, one is more endemic, the other, cosmpolitan. A short primer on Bacillus anthracis to pass along to anyone who may be interested: See Pubmed (combined keyword search) for 'dipeptide[AND]anthracis': 'Statistical analysis of survival in the guinea pigs indicated that PA-MPL-CWS and PA-MPL-TDM-CWS were more efficacious than the currently licensed human anthrax vaccine.' (Click on author reference to read abstract.) 'leukemia[AND]anthracis': Reference #1 'apoptosis[AND]anthracis': Reference #3 'inhibition[AND]anthracis': References #1 and #2 ******************************************************* 'Lethal Factor Metalloproteinases Activity: The recognition that LF(lethal factor) contains a site characteristic of zinc metalloproteinases[Mol. Microbiol. 13:1093] started a process that eventually led to the identity of its catalytic activity. Substitution of Ala for H686, 687 or H690 in the sequence 686-HEFGH-690 destroys the toxicity of LF for macrophages and decreases its zinc-binding ability. This result suggested that LF is a zinc metalloprotein. This hypothesis was supported by the discovery that inhibition of zinc-dependent aminopeptidases(e.g., bestatin, aromatic amino acid amides and hydroxylamates) protect macrophages from LF[ibid., and Biochem. J.(1996)320:687]. The implications that LF acted on the MAPK(mitogen activated protein kinase) pathway led to a series of experiments resulting in the discovery that LF blocks the MAPK pathway and does so by cleaving seven amino acids from the N-terminus of MAPK1[Science(1998)280:734]. It was then found that MAPKK2 was also cleaved. Comparisons of these two proteins suggest that LF recognizes a motif containing several basic peptides and two prolines. Lethal Factor Fusion Proteins: Cellular Mechanism of Action: The anthrax toxins interact to deliver catalytic components, LF and EF, to the cytosol of target cells. The role of PA(protective antigen) is to cause binding of LF and EF to the cell surface, so that they will be internalized by endocytosis and to provide a membrane channel for their translocation from endosomes to the cytosol. This initiates unknown processes, which lead to the lysis of macrophages and to the death of animals.' (The Comprehensive Sourcebook of Bacterial Protein Toxins, London, San Diego, Boston, N.Y., Sydney, Tokyo and Toronto: Academic Press, 1999, p.253] 'Rogel and Hanski[J. Biol. Chem. (1992) 257:22599] have demonstrated that although delivery of the catalytic domain to the target cell interior(translocation) is unaffected by treatment of the cells with trypsin, n-ethylmaleimide or sodium carbonate, cleavage of the toxin to release a 45-kDA catalytic fragment into the cytosol is blocked by n-ethylmaleimide. It is likely that the enzymatic active fragment and the remainder of the toxin molecule that is known to be very proteolytically sensitive[Proc. Nat. Acad. Sci. USA (1976) 73:1926] is rapidly degraded by cellular proteases.' [Bacterial Toxins and Virulence: Factors in Disease, N.Y., Basel, Hong Kong: Marcel Dekker, Inc., 1995, p. 431-2] Using Pubmed combined-keyword searches offer many powerful options. Here are a few more possibilities as research tools: Keywords like amides, sulfur-containing, saponins, apoptosis-inhibiting(counts as one word), antileukemic, as well as any words that seem appropriate within the text of an abstract: 'Effects of Two Saponins Extracted from Polygonatum zanlanscianense on Human Leukemia (HL-60) Cells,' (methyl protdioscin and dioscin has significant inhibitory effects on growth of leukemia cells.) Other possible keywords: Viva-Natural Aster[AND]tartaricus acyclic[AND]peptides Houttuynia(chameleon plant) Bidens acetogenins Asimina Phyllanthus Chelidonium(chelidostatin) Stellaria Polygonatum Polygonum Aglaia N-cinnamoylpyrrole Piper antifungal amides Glycosmis chlorinated amide(s) Aloe bestatin maleimycin bengamides apoptosis[AND]inhibition any keyword: ____[AND]plant " ____[AND]sea " ____[AND]marine " ____[AND]tunicate " ____[AND]sponge " ____[AND]cowhide " ____[AND]tannery macrophage[AND]peritoneal phagocytes[AND]peritoneal Natural Products Updates: Current Developments in Bioorganic Chemistry, V.18(Aug. 2001):432: 'The complete apoptosis of a cell is a rapid process occurring within 24 hours and typically occurring over a much shorter period. Importantly, the membrane integrity of the apoptotic bodies remains, and they are phagocytosed before there is leakage of cytosolic contents into the surrounding tissues to induce an inflammatory response.[Ann. Rev. Immunol.(1999) 17:781].' Cancer Letters, V.173:163 'Inhibition of Apoptosis by Pentachlorophenol in V-Myc-Transfected Rat Epithelial Cells: Relation to Down-Regulation of Gap-Junction Intercellular Communication.' __________________________________________________ Do You Yahoo!? Find a job, post your resume. http://careers.yahoo.com --- from list french-feminism-AT-lists.village.virginia.edu ---
Display software: ArchTracker © Malgosia Askanas, 2000-2005