SDS-page & lipidated proteins - (Dec/18/2007 )

could somebody explain me why a lipidated protein forms a lower band than that of non-lipidated form in SDS-PAGE?

Increased hydrophobicity thus more SDS association?

Which protein?
after lipidation of lipoproteins, you have pepdtide signal cleavage, which means shorter protein and longer migration.

It's a protein (ATG8) that gets conjugated to Phosphatil ethanolammine (PE), in a ubiquitin-like system, important in autophagy, and it's involved in membrane nucleation/expansion. there is no cleavage (a cleavage occurs, but before the lipidation, the difference in migration I mean is between mature form and PE-form), so I think the answer about SDS and hidrophobicity is correct.

anyway, thanks for reply

Is there a stain which is selective for lipid modified proteins in a gel or western?

[quote name='Andry82' date='Dec 22 2007, 04:37 AM' post='120993']
It's a protein (ATG8) that gets conjugated to Phosphatil ethanolammine (PE), in a ubiquitin-like system, important in autophagy, and it's involved in membrane nucleation/expansion. there is no cleavage (a cleavage occurs, but before the lipidation, the difference in migration I mean is between mature form and PE-form), so I think the answer about SDS and hidrophobicity is correct.

How many PE motifs are conjugated to a protein? Through an amide like bond (CO-NH)?