Posted by Larry Hoover on October 4, 2008, at 16:59:18
In reply to Article on how our understanding of receptors migh, posted by mike1975 on September 29, 2008, at 10:42:43
For about 30 years or so, we've been able to extract and purify receptors. Receptors are proteins which "float" in a membrane that is mostly fats, and fat soluble substances, such as cholesterol. We've known for almost as long that receptors need exposure to cholesterol to function.
Earlier this year, the most detailed models of the actual molecular structure of the acetylcholine receptor was published, but it confused many researchers, because there were empty pockets.....spaces that nobody had recognized existed before this.
This particular paper has explained these pockets as being places where cholesterol is actually embedded within the receptor complex. It's found deep within the structure, and also exposed in the active site, where acetylcholine binds. It was shown that the three-dimensional structure of the receptor depends on cholesterol being present, as does the function of the receptor.
As an aside, cholesterol gets far too much bad press, especially with respect to diet. Diet largely controls cholesterol synthesis (90% or more is made in your liver), but dietary cholesterol is generally of no significance.....unless you're one of the unlucky few (3-5% of the population) with a particular genetic susceptibility. Funny, we don't teach everyone to eat as if they're diabetic, but we teach people to avoid cholesterol as if they're unable to regulate it.
Anyway....if my explanation didn't cover your questions, ask again.
Lar
poster:Larry Hoover
thread:854753
URL: http://www.dr-bob.org/babble/20080926/msgs/855754.html