If there are 5 organisms that produce a single type of enzyme, but the amount of that enzyme produced by them is different. So will their enzyme activity vary according to the amount of an enzyme produced by different organisms? Is enzyme activity directly proportional to enzyme production?
In the absence of any form of regulation of the enzyme activity, the activity is directly proportional to the enzyme concentration. However, there may be regulation in the form of inhibitors or activators produced by the organism, or present in its environment, that alter the enzyme activity. Moreover, there may be differences in the sequence of the enzyme between species that affect the activity of the enzyme and/or its stability once it is produced.
Enzyme concentration might also be a factor of regulation of enzyme activity suggesting that the activity is not always proportial to the enzyme concentration; Exemple, autocleaved effect (see, ovotransferrin (OTf), the second major protein in egg albumin which undergoes thiol-linked autocleavage at distinct sites upon reduction) and control of cell proliferation, cancer etc.
I think the "spatial concentration" of proteases might be a key factor of their enzymatic regulation.
PS; We need to define the term concentration of a protease in the cell/organism. Is that ng/vol, ng/topology, pg/DNA concentration etc...
Most proteases are produced as inactive zymogens, that need an activation step (e.g. removal of an inhibitory pro-peptide or dimerization to align the active site residues). Additionally, endogenous inhibitors may affect the total fraction of active enzyme present in the sample. Instead of looking at protease abundance, it's better to look at protease activity (e.g. with a fluorogenic substrate) or at the fraction of active protease (e.g. with an activity-based probe). You can find more info in some reviews that my lab has written, e.g. Verdoes & Verhelst, Biochem. Biophys. Acta 2016 (detection of protease activity in cells and animals).
Hello Lakhan, although this is a year old query, I think I should simplify the matter.
There are several factors to consider. Such as-
1. Specific enzyme activity
2. Productivity of enzyme
3. Protein sequence of the enzymes
4. Ligands
Although 5 organisms synthesize same enzyme, there might be difference in sequences. So, activity may vary. Even the ligands may be different due to the difference in the sequence. Hence the specific enzyme activity, i.e. U/mg may be different. Again, the time required for the expression of same enzyme by 5 different organisms might not be the same. In that case, productivity i.e. U/ml/hr will be different. Moreover, the medium used for culture also influences the enzyme productivity.
Normally, the more enzyme, the more activity. But the substrate should be available too.
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