File spoon-archives/french-feminism.archive/french-feminism_2001/french-feminism.0111, message 3


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.'
 


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