Extremophile
From Proteopedia
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<StructureSection load='1Y7W' size='350' side='right' caption='Structure of alpha-type carbonic anhydrase (dCAII) (PDB entry [[1y7w]])' scene='JMS/sandbox4/Ca/3'> | <StructureSection load='1Y7W' size='350' side='right' caption='Structure of alpha-type carbonic anhydrase (dCAII) (PDB entry [[1y7w]])' scene='JMS/sandbox4/Ca/3'> | ||
| - | Our first example comes from the algae Dunaliella salina, found growing on the shores of the dea sea by Prof. Volcani, working at the Experimental Research Station (now the Volcani Institute), and then housed on the campus of the Daniel Sieff Institute (now the Weizmann Institute). Appropriately, scientist from the Weizmann Institute, Prof Joel Sussman, Dr. Adi Zamir and collegues, crystallized the <scene name='JMS/sandbox4/Ca/3'>structure of an enzyme</scene> that hangs out of the membrane of D. salina. Now, living on the shore of the Dead Sea presents a special problem for the living. While the dead sea is a challenge with its enormous concentration of salt, living on its shores means one must cope with high salt concentrations, but also - normal salt concentrations. That is, the adaptations to high salt must leave open the possibility of living with normal salt concentrations, too. | + | Our first example comes from the algae Dunaliella salina, found growing on the shores of the dea sea by Prof. Volcani, working at the Experimental Research Station (now the Volcani Institute), and then housed on the campus of the Daniel Sieff Institute (now the Weizmann Institute). Appropriately, scientist from the Weizmann Institute, Prof Joel Sussman, Dr. Adi Zamir and collegues, crystallized the <scene name='JMS/sandbox4/Ca/3'>structure of an enzyme</scene> that hangs out of the membrane of D. salina. Now, living on the shore of the Dead Sea presents a special problem for the living. While the dead sea is a challenge with its enormous concentration of salt, living on its shores means one must cope with high salt concentrations, but also - normal salt concentrations. That is, the adaptations to high salt must leave open the possibility of living with normal salt concentrations, too. Water<br /> |
::<big><scene name='JMS/sandbox4/Ca/3'>∆G</scene> = <scene name='JMS/sandbox4/Surface/2'>∆H-T∆S</scene>.</big><br /> | ::<big><scene name='JMS/sandbox4/Ca/3'>∆G</scene> = <scene name='JMS/sandbox4/Surface/2'>∆H-T∆S</scene>.</big><br /> | ||
In the next example, however, I specify the thermodynamic terms which a structural adaptation personifies. For that, we turn to a thermophilic enzyme, also solved by Weizmann Institute lab - Porfessor Yigal Burstein and his team of scientists. | In the next example, however, I specify the thermodynamic terms which a structural adaptation personifies. For that, we turn to a thermophilic enzyme, also solved by Weizmann Institute lab - Porfessor Yigal Burstein and his team of scientists. | ||
Revision as of 19:27, 20 February 2013
Contents |
Extraordinary Proteins
Where there is no man, be a bacteria
Where no man or plant could survive, bacteria have been eking out a living, and some even thriving. From the Dead Sea which has 10 times the concentration of salt in salt sea water to the hot springs heated by the molten center of the earth, that pour forth through vents deep under the sea (see this fantastic Thermophile Video from BBC Wildlife) - in all these hostile environments, life has found footing. To make the question stronger, realize that many things can go wrong, cells could burst or shrivel, DNA can become undone and tattered, protein can unfold into a jumbled mass of amino acids, and membranes made of fat molecules can rip and melt. Environment stress usually achieves all or many of these deadly process to organisms - yet some bacteria survive. To study how the extremophiles (extreme-loving bacteria) survive involves explaining how each of the above processes that should kill the bacteria, in fact do not occur. To understand all of these is a tall order, but to start, in this Proteopedia article, we'll tackle the protein survival under extreme stress problem.
Extremophiles talk in thermodynamics terms
All stresses must be interpreted into the language of thermodynamics, since that is the most faithful representation of the problems the environment brings to proteins, and the way the structures have solved this problem, and found a way to maintain their stability.
The principle equation is:
- ∆G = ∆H - T∆S.
- ∆G = ∆H - T∆S.
Where ∆G is negative, the movement to products in the reaction is spontaneous. This means, for the case of going from unfolded protein to folded protein as the product, a negative ∆G wold correspond to a stable protein structure. The other three terms: ∆H, T, and ∆S correspond to the change in enthalpy, the temperature (in Kalvins), and the change in entropy. Where the product is more stable than the reactants, ∆H will be negative, and the products are more ordered than the reactant, ∆S will be negative. It can be seen from the equation that ∆G becomes more negative for a more negative ∆H or for a less negative ∆S.
At the the Weizmann Institute, scientists discover enzymes in the Dead Sea
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Thermophilic enzymes adapt by changing their Enthalpic and Entropic properties
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Proteopedia Page Contributors and Editors (what is this?)
Joseph M. Steinberger, Joel L. Sussman, Alexander Berchansky, Michal Harel
