Sunday, February 11, 2007

It's not a cure to Mad Cow Disease... yet.

We've all heard of Mad Cow Disease... no not the one that has cows retaliating for the whole cow tipping phenomenon, the one that has everyone scared that if they eat a cow, they are going to go crazy. In case you haven't heard or if you don't know much behind the biology of it, I'll give you a little primer.

Prions are proteins that in their natural state are responsible for... well, we don't know really. A recent Nature article says that we are narrowing down their role...

There is now increasing, albeit patchy, evidence that the process of prion infection might have a vital role in a large number of biological processes—not only in single-celled organisms but also in higher eukaryotes—ranging from adaptation to new environments to the establishment of long-term memory.

...Ok, so it's not narrowed down much.

But anyway the interesting point about these proteins is that when they are folded in the "prion" conformation, they are almost impossible to degrade. Which means they don't go away. Ever. Which is bad in the brain. Even heating to very high temperatures doesn't harm these proteins.

Here is the next really cool thing about prions, well morbidly cool anyway... when a prion protein comes into contact with a native form of the prion protein, the native protein changes conformation and becomes highly stable as well. So not only do prions stick around, but they make others just like them.

And the scary thing about this kind of protein is that a lot of animals have them. Sheep have them, the disease they cause is scrapies. Cows have them, that disease is actually called bovine spongiform encephalitis (BSE). And humans get it, one form of it is called Crutzfeld-Jacob disease. The worst part about it is if we were to eat a cow that had BSE, those prion proteins could start interacting with our normal proteins and give us the human form of the disease.

Recently, a group has produced genetically engineered cows - over a dozen of them - that don't have the message for this protein (December's Nature Biotechnology). Which means they can't get the disease. These cows are almost 2 years old now and... At over 20 months of age, the cattle are clinically, physiologically, histopathologically, immunologically and reproductively normal.

So, I'm left with a nagging question... What the heck is this protein for?


Bill said...

Prions are probably just out to make copies of themselves, and it looks like they're doing an awfully good job of it. Plus they're virtually indestructible. What more can you ask?

Christopher said...

In terms of a physiological role for the native cellular prion protein (PrPC), this protein has been shown to protect cells against oxidative stress (J. Biol. Chem. Vol. 280, pp. 35914-35921, 2005). Reactive oxygen species cause cleavage of PrPC at the end of of the copper-binding octapeptide repeats, a process termed beta-cleavage. Cells expressing mutated forms of PrPC (instead of wild-type PrPC) were more susceptible to oxidative stress, exhibited reduced viability, decreased glutathione peroxidase activity and higher levels of intracellular free radicals. The authors concluded that beta-cleavage of the native form of PrPC is an early and critical event in the protection of cells from oxidative stress.

Anonymous said...


I haven't been keeping up - is there a causal connection between BSE & Creutzfeldt-Jakob, or is this based on small sample statistics?

Howard said...

Kuru is also a bit like BSE.

Jose Andrews said...

Jose Andrews is my name, Some people keep questioning God, asking him why he allowed Satan to put in the world deadly diseases, but they never know that anything happening in this life, is just for a particular reason. Here is my story on how I was cured of schizophrenia (Brain Disease) by a herbal doctor Uwadia Amneifo using his herbal mixture. Few months ago, I realized I had some problem with my system, and later on I begin to forget things easily. I complained to my doctor after his text he said just a little problem with me, but that soon I will be fine. He prescribed for me and I was taking medicine according to his prescription but my condition was getting worse instead of coming down. So I went back to my doctor after some time, he said am having issues with my brain, this continues gradually until it became worse and I was diagnosed of schizophrenia (Brain Disease) and this disease is same with SCJD. My doctor told me there is no cure to this disease that I have to live and die with it. It continued for one month and my system was almost shutting down before my cousin brother came to my house to visit and broke to us the news about a herbal doctor he heard about called doctor Uwadia Amenifo that cured some body of SCJD . So he explained how he heard about this herbal doctor uwadia Amenifo and the kind of terrible diseases this doctor have cured. His words were very impressing and I had to give the doctor a try. We made contact with him and he said he can cure me. So my cousin made all necessary arrangement with him, and he prepared herbs and send to me in USA. I took the herbs according to his prescription and behold to cut long story short his herbs works perfectly well, and cured me of my schizophrenia (Brain Disease). Today I am hale and healthy and evidence of my healthiness can been seen in this piece of note I wrote myself to tell the world about Herbal Doctor Uwadia Amenifo. Please if you know anyone suffering from brain disease, in a hurry contact Doctor Uwadia Amenifo on his email (, and his cell no is +2349052015874. I wish all suffering from brain problem quick recovery.

Jose Andrews said...
This comment has been removed by a blog administrator.