Over-expression using maltose-binding protein

[Arsenio Villarejo]

Hi,

	I'm trying to over-express a protein using the 
maltose-binding protein system. My protein is quite hydrophobic and 
has an isoelectric point close to 9.5. After cutting the fusion 
protein with Xa factor, I tried to purify the cleaved protein by ion 
exchange chromatography. At this point, I lost my protein because it 
binds to everything (dialisis membranes, centricon membranes,....). 
So, I should keep a relative high salt concentration in the mixture 
to avoid any precipitation of my protein.

	What kind of chromatography technique can I used for 
separating the maltose binding protein from my protein (with ca. 30 
kDa)??.

	Any help or new idea will be wellcome.

	Thanks a lot in advance.

	Arsenio Villarejo
-- 
Arsenio Villarejo                            Phone:  +46 90 7867648
Department of Plant Physiology               Fax:    +46 90 7866676
Umea University
S-901 87 Umea, Sweden     E-mail: Arsenio.villarejo at plantphys.umu.se

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