Sunday, April 24, 2011

Nitric Oxide Synthase: One Enzyme, Many Functions

I like to think of Nitric Oxide Synthase as having multiple personalities. It can be mean--it can catalyze the production of nitric oxide in large quantities, which is used by the immune system to kill pathogens. It can also be really nice--it can catalyze the production of small quantities of nitric oxide which, if administered during a heart attack, causes muscle cells around blood vessels to relax and decrease glycolytic activity. 
But not only that...it can also talk!  It acts as a messenger in endothelial cells and helps regulate blood pressure by producing NO gas that is membrane permeable and vaso-active.

It even looks like an enzyme with multiple personalities...

angry face


nice face!
legs!

















Nitric Oxide Synthase catalyzes the reaction that produces nitric oxide from L-arginine. NOS is found in three isoforms: brain NOS (bNOS) or neuronal NOS (nNOS), endothelial NOS (eNOS), and inducible calcium-independent NOS (iNOS). 

NO has many important roles in the body the demand its synthesis via NOS. It activates cGMP, which mediates relaxation and prevents platelet aggregation. NO can also decrease glycolytic activity that results from heart attack by binding to glyceraldehde-3-phosphate dehydrogenase and inhibiding cellular respiration. NO also is useful in inactivating oxygen free radicals and hindering cell toxicity. 
On the other hand, under different conditions NO can react with free radical oxygen to make toxins to fight pathogens. 

The production of NO catalyzed by NOS is an extremely important mechanism due to its many physiological, biological, and pathophysiological effects in the body.
Its multiple personalities, multiple functions, and a structure that reflects those, makes it pretty much the coolest. protein. ever. :)

Works Cited:
Abu-Soud et al. “Nitric Oxide Synthases Reveal a Role for Calmodulin in Controlling Electron Transfer”. Proceedings of the National Academy of Sciences of the United States of America
90.22 (Nov. 15, 1993), pp. 10769-10772 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC303065/

Goodsell, David. Protein Data Bank Molecule of the Month: Nitric Oxide Synthase. January 2011. http://www.pdb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb133_1.html&sms_ss=twitter&at_xt=4d3eb0d8118b9af3,0

Mungrue, Imran et al. “The Role of NOS in Heart Failure: Lessons from Murine Genetic Models.” Heart Failure Reviews.7.4 (2002): 407-10. http://www.ncbi.nlm.nih.gov/pubmed/12379825

Rossellin, Marinella et al. “Role of Nitric Oxide in the Biology, Physiology, and Pathophysiology of Reproduction”. European Society for Human Reproduction and Embryology. 4.1 (1998). 3-24.http://humupd.oxfordjournals.org/content/4/1/3.abstract

3 comments:

  1. Looks nice! Just a couple of things. If it has legs can it walk? And on a slightly more serious note, you could possibly spice up the font just a bit. Oh and "protein. ever." aren't sentences. : )

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  2. I'm with Josh... the font could be spiced up a little :)

    Nice work!

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  3. Great protein and good work! And it is a strange one - I would have never guessed we have proteins that MAKE radicals in our body. One typo - in your second-to-last paragraph, you write "inhibiding" instead of "inhibiting."

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