Extremophile: Difference between revisions

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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.
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 ==
== Negative surface charge and solubility ==


<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. Water<br />
In salty water, most proteins aggregate. That protein's on the outside of some archea in the dead sea manage to remain soluble in solutions entering up to one salt molecule for every two H20 molecules is quite stunning. Over a decade's work, Joel SUssman, Ada Zamir, and others at Weizmann Institute and Tel Aviv University have shown that the negative density on the surface of proteins turn them into anion-like, hunce solube in salt-containing solutions. The more recent research involved halophles, and showing that their intermediate negative surface charge enables them to walk the tightrope between little salt and salf-saturating conditions, repectively. Still mysterious, though, is why all halophilic proteins aren't for the same price halotolerant - what use is all that extra negative surface charge?
::<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 - Professor Yigal Burstein and his team of scientists.


</StructureSection>
</StructureSection>
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{{Clear}}
{{Clear}}
== Thermophilic enzymes adapt by changing their Enthalpic and Entropic properties ==
== Proline in Entropy and between-chain ion-network bonding ==


<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'>
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