freeze dried powder - (May/14/2012 )

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.

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

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

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...

Sid on Tue May 15 03:03:57 2012 said:

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

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.

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

by definition, freeze drying is performed at low temperature.