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Synthetic Molecules Emulate Enzyme Behavior
FiReaNGeL writes "Ohio State University chemists have created a synthetic catalyst that can fold its molecular structure into a specific shape for a specific job, similar to natural catalysts. In tests, the chemists caused the catalysts to twist one way or the other, either to form one chemical product or its mirror image. They confirmed the shape of the molecules at each step using techniques such as nuclear magnetic resonance spectroscopy. Being able to quickly produce a catalyst of a particular shape would be a boon for the pharmaceutical and chemical industries."
Things like converting glucose to ATP in the body achieve ~70% efficiency.
Glucose to ATP using glycolysis followed by cellular respiration using the electron transport, the most efficient process, is only about 40% efficient. The rest of the energy is released as heat, which is good for warm blooded creatures like ourselves. In babies, the brown fat makes cellular respiration even less efficient, which keeps them warm.
Scientists have been able to design new proteins that can catalyze reactions. In two landmark papers just this year (De Novo Computational Design of Retro-Aldol Enzymes, Science 2008 319, 1387; Kemp elimination catalysts by computational enzyme design, Nature 2008 453, 190), David Baker's group at the University of Washington was able to computationally design two entirely new enzymes from scratch. Of course, there's still a lot of work to be done as these enzymes are not nearly as efficient as natural enzymes, but these breakthroughs open up many great possibilities. Here's a summary describing the results of the Science paper.
Flamebait?! Are you people kidding me?! That was a Homer Simpson quote! For the freaking love of Pete. Look, here's what was written:
"They confirmed the shape of the molecules at each step using techniques such as nuclear magnetic resonance spectroscopy."
Good freaking grief people. Get a sense of humor.
Natural catalysts, such as enzymes in the human body that help us digest food, get around this problem by shape-shifting to suit the task at hand. (...)
Natural catalysts reconfigure themselves over and over again in response to different chemical cues -- as enzymes do in the body, for example.
Actually enzymes do a have a somewhat *fixed* fold for a specific (type of) reaction and don't just catalyse this then that etc. They can be highly selective for only one substance / functional chemical group or not. However they certainly don't reconfigure themselves (we're not talking about allosteric enzymes). The cell just produces a different set of enzymes to adjust to new conditions.
In tests, the chemists caused the catalysts to twist one way or the other, either to form one chemical product or its mirror image.
They better have this working 'error-free'. Having a mixture of both shapes can get you into big trouble (http://en.wikipedia.org/wiki/Thalidomide).
"For many chemical reactions to work, molecules must be able to fit a catalyst like a hand fits a glove," RajanBabu said. "Our synthetic molecules are special because they're flexible. It doesn't matter if the hand is a small hand or a big hand, the 'glove' will change its shape to fit it, as long as there is even a slight chemical preference for one of the hands. The 'flexible glove' will find a way to make a better fit, and so it will assist in specifically making one of the mirror image forms."
I'm not sure this is so good - wouldn't you want them to behave like enzymes aswell, being highly selective? And last but not least there is no comparison offered to *real* enzymes in terms of 'speed' and what kind of reactions besides fatty acid hydrogenation are possible.
There are different energy calculations for this. Calculated at STP, the number is about 38%. But in actual cellular conditions, the calculated value is anywhere from 50% to 70%, depending especially on the ratio of ADP to ATP.
(can't think of any enzyme-deficient diseases off the top of my head, but there must be some)
How about phenylketonuria, for one?
'He who has to break a thing to find out what it is, has left the path of wisdom.' -- Gandalf to Saruman
I appreciate your enthusiasm but that list contains not one single cure. Only prevention that is about 97% effective. Most also require booster shots to keep the protection active. If you actually contract one of those diseases we can make you as comfortable as possible and let it run it's course. But there are no cures. Pharms get paid for each person that receive those inoculations as well. Face it there is NO Financial incentive to cure a disease if you can make drugs to treat it.
Why bother