PEPC in maize seedlings

[angelyn1985]

After a series of purification of PEPC from maize seedlings (i don't think it was absolutely pure), I ran the mixture through SDS-PAGE, there were 2 visible bands on it. Knowing that maize PEPC contains 4 identical subunits with Mr of about 110KD, I am confused by the result that both the 2 bands (one was 110KD another was bout 65KD) were visible after a western blot using a polyclonal antibody for PEPC.

Anyone has a clue why the 65KD band was visible after the western blot? And what protein could it be?

Cheers.

[Cat]

First of all, your info does not match the size expected (previously reported 99KD) isolated from leaves. Note that you are using whole seedling AND most likely a different cultivar (Zea mays L. var. Golden Cross Bantam T51 was previously used).
Another paper reports different isoforms isolated from leaves and roots. Read: http://www.jbc.org/cgi/content/abstract/261/13/6132
for more information.