Detoxification of HCN

Stefanie Galgon smg4 at DANA.UCC.NAU.EDU
Wed Jul 14 15:51:21 EST 1999


Steve & all,

Watch out -- I've had my coffee!!! ;-)

I do not recall if someone already discussed HCN!  Bare with me here...
(if you would rather check out Wink's version, you'll find the information
in Dey & Harborne pp 454-6).

Cyanogenic glycosides are hydrolyzed and decomposed to aldehydes / ketones
plus HCN.  HCN is toxic to mammals, insects, microorganisms, and...
PLANTS! (you knew I'd get there sooner or later, right?).  All organisms
have a biochemical process of detoxifying this stuff.  Plants are amazing
in that they can get rid of it, by using it (I know, I know... plants do
not have a will) as a defense mechanism.  Fine line here?  Maybe.
Cyanogenic glycosides are stored in the central vacuole (I believe someone
did bring this up... sorry if I am being repetitive).  HCN is probably
carriered or vesicled from cytoplasm to vacuole.  Since HCN IS toxic to
plants, hey, a detoxification pathway exists!

Detoxification of HCN by plants:
HCN + cysteine --> 3-cyanoalanine --> asn --> asparagine

asparagine is a storage and transport compound (catalyzes the
deamination of asparagine).

I think that is a darn good example. Please feel free to correct me on
any misrepresented information.


Ref: Dey & Harborne, 1997, Plant Biochemistry -- aka The Bible!

Steffi



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Stefanie Galgon			lab/message: (520) 523-7735
Department of Biology		
Northern Arizona University	smg4 at dana.ucc.nau.edu

"Life is a banquet, and most poor suckers are starving to death"  
Auntie Mame
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