Blue Protein?!

[beatriz at animal.ufl.edu]

In article <1993Oct26.180345.1 at vcp1.vcp.monash.edu.au> brendan at vcp1.vcp.
monash.edu.au writes:
>I've been purifying a protein from human plasma and 
along the way
>I've collected a fraction containing a blue protein. On a 12% 
SDS>gel this fraction shows three major bands near 20, 30 and 60kDa.>Does 
anybody have any idea what the blue protein is? I have heard>that blood does 
contain one blue protein. All suggestions are>welcome.
>
>Brendan Duggan

Brendan,

it's possible you are enriching for type-5 tartrate resistant acid 
phosphatase. It is an iron binding protein with a mw of about 33 kDa. The 
porcine counterpart, uteroferrin, is referred to as the purple protein. 
 
Good luck,
Beatriz.