enzyme denatureization

[bugmenot]

enzyme denatureization

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Post by bugmenot » Sun Nov 26, 2006 11:02 pm

I know changes in pH and high temperatures can denature an enzyme, but what about low temperatures? Would putting an enzyme that is found in 90C conditions in a 4C cooler denature it?

Thanks.

[oppox]

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Post by oppox » Sun Nov 26, 2006 11:59 pm

I know that a friend of mine happened to denaturate his protein when he tried to store it in a freezer, however it dont apply to all proteins. Taq polymerase for instanse is stored below zero, it comes from a heat resistent bacteria. Its hard to say if yours will denaturate.

[Vibrio]

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Post by Vibrio » Sat Dec 16, 2006 11:44 pm

I cannot see how an enzyme would denature in a low temp. Heat speeds things up, so wouldn't it just either stay the same or not work as well or something (in a low temp)?

[SororSaudade]

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Post by SororSaudade » Sun Dec 17, 2006 12:59 am

generally low temperatures inactivate enzymes. I don't know if a long time storage can damage them (it happens with DNA). there may be some exceptions, probably.

[destiny]

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Post by destiny » Sun Dec 17, 2006 10:32 am

I also think low temperature would inactivate the enzyme.

[victor]

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Post by victor » Sun Dec 17, 2006 12:44 pm

yup, I think like that too. The reason I think is related to the secondary and tertiary structure of the enzyme, where hydrogen binding and hydrophobic interaction would not be same as the active enzyme (you'll get this idea when you imagine how ice float in water )

But one question that still confusing me, I found that lipase is still active even in the temperature 0 ºC......

[oppox]

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Post by oppox » Sun Dec 17, 2006 2:25 pm

I my self thought it to be safe to store proteins in a freezer, but then my friend told me about his protein. Also there are something called cold denaturation.

[wbla3335]

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Post by wbla3335 » Mon Dec 18, 2006 8:15 am

Many proteins can denature if the medium they are in freezes. Most enzymes used in molecular biology that are stored at -20 C are kept in a glycerol buffer that prevents freezing. You could try doing this. If you'd like to store your proteins frozen, you could try snap freezing them in liquid nitrogen. This process seems to cause less denaturation for many proteins.

[01addiv-llangirb]

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Post by 01addiv-llangirb » Wed Dec 20, 2006 12:17 pm

Enzymes have come out of ice very deep in the antartic ok so i doubt a standard freezer will have much effect on there action if warmed up again.

[sachin]

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Post by sachin » Wed Dec 20, 2006 4:04 pm

Ice Cool Enzyme==Low acivity of Enzyme.