[darkswill]

hi guys, do isoelectric precipitation effective method to separate protein from a mixture of carbohydrates?

please help me... thanks

[Yggdrasil]

It depends what you want to do.  Isoelectric precipitation will separate your protein from carbohydrates, but it often leads to irreversible aggregation and denaturation of your protein.  So, it is an effective way of removing contaminaiting proteins from a solution of carbohydrates, but it would not be ideal if you wanted to purify a sample of protein.  A better choice for purifying protein from a mixture of carbohydrates would be to use ammonium sulfate precipitation.  This works in the same way, but the it usually will not denature your protein.

So, if you want to purify the carbohydrates use isoelectric precipitation.  If you want to purify the protein, go with the ammonium sulfate precipitation.

[darkswill]

thanks alot for the information...

but do ammonium sulfate precipitation effective in large scale precipitation of protein?

[darkswill]

in addition, can we separate the two substance without destrying one of them?
in other words, can we isolate and purify both carbohydrates and protein?

if, yes what method will be use?

[Yggdrasil]

What scale do you consider large scale (e.g from what volume are you purifying the proteins)?  If you have a 100mL solution of protein/carbohydrate, you would need on the order of 30-40g of ammonium sulfate to precipitate out the protein, which is reasonable.  I don't know how well the procedure scales up to larger quantities.

In theory, if you precipitate out the protein, your pellet should contain mostly protein (and other low solubility substances) while your solution will contain lots of ammonium sulfate, your carbohydrate, and other high solubility substances.  The ammonium sulfate precipitation would not destroy the carbohydrate.

[darkswill]

Ah so I see thank you very much sir for your information....

[AhmedEzatAlzawalaty]

is chromatography a possible method?

[darkswill]

Ammonium Sulfate Precipitation was effective method to isolate protein leaving the carbohydrates at aqueous solution with the ammonium sulfate...Now, my  question is how can we recover ammonium sulfate from the mixture of carbohydrates?

[Yggdrasil]

How big are the carbohydrates?  Can you use a desalting column?  Dialysis?

[darkswill]

How big are the carbohydrates?  Can you use a desalting column?  Dialysis?

Yes, it's true that desalting column dialysis was effective but in small quantity only... what about we have 500 - 1000 L of solution of protein/carbohydrate and we might be using 150 - 400 g of ammonium sulfateand to think of, its diffecult to separate ammonium sulfate in large quantity and shorter time...

hmm... is it effective to convert the carbohydrates containg ammonium sulfate into alcohol followed by distillation process?

[Yggdrasil]

I've never worked on that scale before, so I don't know what the best methods for you would be.  Perhaps people in the chemical engineering section may have some better insights.

[darkswill]

ok i'll try to post in that forum...

one more thing, i have read about membrane fitration of waste water using Ultrafiltration, nanofiltration, reverse osmosis, microfiltration, and electrodialysis. i found it interesting and in your own opinion, is it possible to apply it using proten/carbohydrate solution?

[Yggdrasil]

You may be able to.  Proteins are fairly large so they probably wouldn't pass through your filters.  Your carbohydrate may or may not pass through depending on its size and the properties of your filters.

[darkswill]

Great! so i'll try to do some experiments.
thank you very much.
this forum help me a lot.

[kira2000]

to remove ammonium sulfate in the solution, i would prefer to use the RO (reverse osmosis). i think it is more effective.