[augustfan]

I want to ask how I can identify the presence of a glycoprotein?

My lecture notes said it is with the use of a DIG kit. I'd done a search about it but it retrns with not much important results.

Also, in concerning with homogenising buffer, what is the reason for adding EDTA? I know it's use to chelate Ca2+ and Mg2+, but why? Another question will be the use of urea in isoelectric focusing, is it used to stabilise protein?

Sorry but I am new to here, please tell me if I had any kind of wrong posting format.

[Yggdrasil]

I'm not familiar with glycoprotein detection, so I can't answer the first question, unfortunately.

EDTA helps prevent proteolysis since many proteases use metal ions as essential cofactors (e.g. the zinc metalloproteases).

Urea breaks up hydrogen-bonding interactions, which helps denature proteins for electrophoresis.

[augustfan]

Thanks for your information.
A further discussion to your answer, so it is not possible to retain the activity of a protein / an enzyme after IEF as urea is added.
Because Urea denatures a protein?

[Yggdrasil]

Yes.  Because urea denatures proteins, proteins will not retain their activity in the presence of high concentrations of urea.  However, denaturation using urea is sometimes reversible.  So if you can remove the urea, you may be able to refold your protein and recover its activity.

[augustfan]

HELP~~~

Is it possible to show and isolate glycoproteins from a mixture of "glycoproteins and urinary GAGS" ??

I am taking a biochem Lab exam tmr~~please help if u know about the informaton

Thanks