7 replies to this topic

[Sid]

Dear all,

I was wondering, if i were to isolate enzyme from a freeze-dried mushroom in powder form, will the enzyme that i'm looking for be inactive due to the freeze-drying applied on the mushroom?

if the enzyme is inactive, how could i activate it back? by growing the mushroom back on broth? or is there any other way?

Thank you.

[mdfenko]

some proteins should be fine, some will be irreversibly denatured.

[Sid]

thank you for you reply,

I am trying to isolate fibrinolytic enzyme from this mushroom, but the thing is, this mushroom comes in a freeze dried powder form, which left me thinking whether the enzyme should be active or not.

some of the journals I've read used freeze-dried to purify the enzyme but it was done in a much cooler environment <4 degrees

[Inmost sun]

it seems to be a protease which are by trend more robust than other enzymes; you should have an in vitro standard enzyme assay for your enzyme to monitor yield and recovery after each purification step...

[mdfenko]

Sid, on 14 May 2012 - 07:03 PM, said:

some of the journals I've read used freeze-dried to purify the enzyme but it was done in a much cooler environment <4 degrees

handling at lower temperatures (working in a cold room or keeping the sample on ice) slows down degradation of the protein.

Edited by mdfenko, 15 May 2012 - 11:30 AM.

[hobglobin]

Though not an expert with proteins, freeze-drying is usually a quite mild method to conserve samples. So if the samples where first frozen promptly e.g. by immersing them in liquid nitrogen and then freeze dried (also at temperatures below -20°C), then samples are dry and usually quite stable if stored properly (not wet and/or warm). Proteins also should be okay (more or less), especially if the "cold chain" wasn't interrupted. This I also would keep when working with them, as mentioned before.

[Sid]

Thank you all for your replies,

yes with low temperature then maybe i could savage something but then again i need to check back with the supplier  of this mushroom whether the process of their freeze dried are done at low temperature

[mdfenko]

by definition, freeze drying is performed at low temperature.