Transcript Document

Black Mamba Snake
Venom
Ifeoma Romaine
Tamara Brooks
The Snake
 Fastest snake in
the world (4)
 speeds up to 12
mph
 2nd largest
venous snake in
the world (4)
 Average length –
8 ft.
 Longest length –
14 ft.
Tan areas indicate area where Black
Mamba is found
 Found in SubSaharan Africa
The Snake
 Classification (4)
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder:
Serpentes
 Family: Elapidae
 Genus:
Dendroaspis
 Species: D.
polylepis
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The Snake
Are olive, brown,
gray, or sometimes
khaki with a cream
underbelly
Named for color of
lining inside mouth
(4)
Found in low, open
habitats, rocky
places or open
woodlands
The Snake
Breed once a year (5)
No other interaction besides
breeding and female
abandons eggs after laying
them (5)
Oviparous with young fully
functional upon hatching (5)
The Strategy
Avoid confrontation but
become aggressive when
threatened. (5)
Raise head up to 1 meter
off the ground (5)
Rapid, numerous strikes
followed by flee (5)
 Depends on reason of bite
The Strategy
Diurnal and hunts both during
the day and at night (4)
When hunting small animals, it
delivers one bite then allows
venom to take over (4)
Stalks prey until death
When hunting birds, clings to
animal to prevent it from flying
away (4)
The Venom
LD50 of 0.250.32 mg/kg
One bite
delivers 100120mg on
average
 Maximum 400
mg
 10 to 15 mg
is deadly to a
human adult
 Contains
 Calciseptine
 Toxin 1
 Toxin K
The Dendrotoxin
Dendrotoxin
Two: long and
short chain
“toxin k” (2)
57 Amino acid
sequence (short) (2)
59 or 60 in the long
Highly specific (6)
Dendrotoxin in channel
The Dendrotoxin
Mechanism
Potassium channel blocker(1)
Specific blocker of noninactivating Kv1.1, voltage
gated K+ channels (1)
Facilitate Ach release from
the presynaptic
membrane(2)
 Kv1.1 channels produce sustained outward potassium
currents in response to low changes in membrane
potential away from resting (3)
The Dendrotoxin
Mechanism
The blockage of potassium
channels prevent the
repolarization of nerve and
muscle cells
Increases the release of
neurotransmitters
Prevents the relaxation of
muscle cells
Calciseptine
 Natural peptide
consisting of 60
amino acids with
four disulfide
bonds. (6)
Highly selective
antagonist or
agonist
Calciseptine Mechanism
Agonist in skeletal muscle
Increases amplitude of action
potentials
Antagonist in cardiac and
smooth muscle
Blocks K+ induced contraction in
aortic smooth muscle
Blocks spontaneous contraction of
uterine muscle and portal vein.
Calciseptine Mechanism
Blocks both Ca2+
and Na+ modes of
L-type Ca channel
responsible for
normal myocardial
and vascular
smooth muscle
contractility.
L Type Ca2+ Channel
L Type Calcium Channel (7)
Long-lasting voltage-gated Calcium
Channels are found in both
excitable and non-excitable tissue.
They are responsible for normal
myocardial and vascular smooth
muscle contractility.
Blockage can abolish contractions
in cardiac and smooth muscle
L Type Ca2+ Channel
Five subunits make up the L-type
channel and alpha-1 subunit is the
binding site for calcium-based
antagonists (6)
 Two distinct functions:
as voltage sensors, regulate the release
of Ca2+ by the sarcoplasmic reticulum (6)
 Channels are permeate to Ca2+ giving
rise to very slowly activated Ca2+
currents (6)
The Relevance
One of the most dangerous
snakes (5)
venom can kill within 20 minutes
Combination of speed,
unpredictable aggression, and
potent venom (5)
Help control pest population
eat small rodents (5)
Conclusion
Not an endangered species, but
problem of humans imposing on
habitat (5)
Venom is toxic to about
everything. (5)
Venom can induce the failure of
major organ systems and
eventually cause death
The Trivia
 Nike’s “Air Jordan XIX” were
designed after this snake (4)
Polymers used to cover laces
resemble black snake skin
The 1982 British horror film
"Venom" (starring Klaus Kinski)
featured a black mamba,
delivered to a young boy by
mistake, and set loose in his
house just as a kidnap plot went
awry (4)
The Trivia
 Uma Thurman's character Beatrix
Kiddo in the Kill Bill movie series has
the codename "Black Mamba" - all
DiVA members have snake
codenames. The character of Budd
was killed by a black mamba planted
in a suitcase full of money. As he lay
dying, Elle Driver, the one responsible
for planting the snake, reads to him a
compilation of facts about the snake's
venom (4)
References
(1)Calbiochem. www.emdbiosciences.com/Shared images.
Downloaded May1, 2007.
(2) Errington, Adam C., Thomas Stohr, and George Lees. Voltage
Gated ion Channels: Targets for Anticonvulsant Drugs. Current
Topics in Medicinal Chemistry. Vol 5: 15-30.
(3) Imredy, John P., and Rodercik Mackinnon. Energetic and
Structural Interactions between δ-Dendrotoxin and a
Voltage-gated Potassium Channels. 2000. Journal of
Molecular Biology. Vol. 296:1282-1294.
(4) Mamba. http:/./en.wikipedia.org/wiki/Mamba. Downloaded May
2, 2007.
(5) Schott, Randy. Dendroaspis polylepis.
www.animaldiversity.ummz.umich.edu/site/accounts/info.
Downloaded May 2, 2007.
(6) Garcia, M.C, et. al., Calciseptine, a Ca2+ Channel Blocker, Has
Agonist Actions on L-type Ca2+ Currents of Frog and Mammalian
Skeletal Muscle. 2001. Journal of Membrane Biology. Vol 184:
121-129
(7) L-Type Calcium Channel. http://www.online-medicaldictionary.org/L+Type+Calcium+Channel.asp?q=L+Type+Calciu
m+Channel