looking for commercially-available high MW protein

[Dr Engelbert Buxbaum]

peng.zhixiang at uvm.edu wrote:

> Hi, 
> I am working with a protein which shows an approximately 470 kDa band
> in Western blotting .My problem is, I do not know if there is a
> protein around 450~500  kDa that are commercially available. Does
> anybody know such protein standards or a purified protein, ideally of
> around 470 kDa, which is supplied by manufacturers?
> Thanks in advance for advice!

Most proteins in that MW-range are multimers and can not be used in
denaturing techzniques like SDS-PAGE. However, I darkly recall seeing
high-MW standards made from chemically cross-linked serum albumine in
some catalogue or the other.