His-tagged protein and SDS-PAGE migration

David R. Bell david.bell at nottingham.ac.uk
Mon Mar 30 17:41:58 EST 1998

The same thing is true for just about all cytochromes P450: they
typically have an Mr of 58-60 kDa, and migrate at 52kDa by 
P450s are not tremendously hydrophobic although they do live in the
endoplasmic reticulum. So aberrant migration is quite likely if an
introduced domain interrupts tertiary structure or a hydrophobic domain.

On Fri, 27 Mar 1998 12:55:43 -0800, Dr E. Buxbaum wrote:

:>> (although I've never seen a protein migrate faster than expected
:>> on SDS-PAGE... how about anyone else?)
:>That can happen with very hydrophobic proteins (for example
:>transmembrane proteins), which bind more SDS than they should for their
:>size. A typical example would be the Na/K-ATPase alpha subunit, which
:>has a MW of 114 (from sequence), but runs at about 80 kDa.

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