Relationship between total protein and enzyme activity

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Relationship between total protein and enzyme activity

Post by schroddycat » Sun Sep 02, 2012 12:34 pm

Dear all, appreciate your comments here.

I'm currently extracting GAD enzyme (Glutamate decarboxylase) by doing enzymatic lysis onto the fungus Aspergillus Oryzae.The lytic enzymatic cocktail was Yatalase, which composing of Chitinase, Chitobiase, Chitosanase, beta-1,3-glucanase and Protease.

I used the cocktail (10 mg/ml) to lyse 5, 10, 20, 30, 40, 50, & 60% w/v of fungal concentration. After incubation time (60 mins), the supernatant was collected for determining total protein (Bradford reagent) and enzymatic activity (GABA Assay).

Here's my finding: total protein increased proportionately with fungal cell concentration. However, total activity and specific activity of GAD enzyme decreased from 30% w/v fungal cell concentration. IMO, I thought total activity of GAD would increase with total protein i.e. more proteins released from fungal cells, more GAD collected as well. Is this result usual or unusual? What phenonmenon caused it?


Fungus (5, 10, 20, 30, 40, 50, & 60% w/v) Undergo enzymatic lysis. Enzyme of interest: GAD

Total protein: increases
Total activity of GAD: decrease
Specific activity of GAD: decrease


Not sure how to interpret the result.

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Post by JackBean » Mon Sep 03, 2012 8:41 am

Just for some reason more lytic enzymes do not help with more activity. Especially if you add protease, your enzyme will be probably degraded.

Cis or trans? That's what matters.

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