[asday7gas]

Hi, I have two questions that interest me related of proteins and PI:

1) Phosphorylation is a modification after the translation of of proteins. The addition of molecular mass protein X after phosphorylation is 80Da, when only a part (!) Of the molecules of the protein takes to phosphorylation.
Is it true that you can identify phosphorylation through differences in pI of the protein phosphorylated and non-phosphorylated?

2) Is it correct to say of proteins may pass a greater distance in SDS PAGE If the PI are lower, even that the Mw (Dalton kilobytes) bigger?

Thank you very very much!

[Babcock_Hall]

Welcome to the forum.  It is a forum policy that you must show your attempt to answer a question before we can help you.  Perhaps a good way to start is for you to define pI and perhaps discuss how pI and amino acid composition are related.

[Babcock_Hall]

If a polypeptide has a large number of basic residues, does this affect the pI.  What about a large number of acidic residues?

[Babcock_Hall]

@OP,
One can see the difference in mobility in native PAGE and ion-exchange HPLC, among other techniques.