Biology-Online • View topic - Free drug concentration

## Free drug concentration

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### Free drug concentration

If,
Free protein = [(Total protein - Total drug -Dissociation constant)] (+/-) under root of (Total protein - Total drug -Dissociation constant)^2 + 4 (dissociation Constant * Total Protein) divided by 2
If Total protein - 0.035 g /microliter,
Total drug - 3319.246 x 10^-15 moles/l (Molecular weight of drug - 337.41 g/mole)
Dissociation constant = 0.27 nM,
How to calculate the free protein, Above is quadratic equaltion,
As the unit dissociation constant of drug is in nM, while that of total protein and total drug is in different units, How to calculate the free protein ?

Is there any way to convert 0.27 nM in to some other unit that can be used for calculation?
carbonp
Garter

Posts: 7
Joined: Tue Oct 13, 2009 11:35 pm

### Re: Free drug concentration

First of all, I don't think, you are supposed to substract the diss. const. from the protein amount
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

JackBean
Inland Taipan

Posts: 5694
Joined: Mon Sep 14, 2009 7:12 pm

Sorry its addition of dissociation constant. but formula does not say multiplication of dissociation constant.
carbonp
Garter

Posts: 7
Joined: Tue Oct 13, 2009 11:35 pm

Sorry, I don't get it.
Anyway, it doesn't make much sense to substract/add the dissociation constant from/to protein/drug amount
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

JackBean
Inland Taipan

Posts: 5694
Joined: Mon Sep 14, 2009 7:12 pm