Intrinsic factor (IF), also known as ​gastric intrinsic factor (GIF), is a glycoprotein produced by the parietal cells of the stomach. It is necessary for the absorption of vitamin B12 l in the ileum of the small intestine. The gastric intrinsic factor protein is encoded by the GIF gene in humans.

Sequence: 
MAWFALYLLSLLWATAGTSTQTQSSCSVPSAQEPLVNGIQVLMENSVTSSAYPNPSILIAMNLAGAYNLKAQKLLTYQLMSSDNNDLTIGQ
LGLTIMALTSSCRDPGDKVSILQRQMENWAPSSPNAEASAFYGPSLAILALCQKNSEATLPIAVRFAKTLLANSSPFNVDTGAMATLALTCM
YNKIPVGSEEGYRSLFGQVLKDIVEKISMKIKDNGIIGDIYSTGLAMQALSVTPEPSKKEWNCKKTTDMILNEIKQGKFHNPMSIAQILPSLK
GKTYLDVPQVTCSPDHEVQPTLPSNPGPGPTSASNITVIYTINNQLRGVELLFNETINVSVKSGSVLLVVLEEAQRKNPMFKFETTMTSWG
LVVSSINNIAENVNHKTYWQFLSGVTPLNEGVADYIPFNHEHITANFTQY with polyhistidine tag at the C-terminus

Source:
Escherichia coli

Endotoxin Test:
<0.1 EU per 1 μg of the protein by the LAL method. Purity:
>98% as determined by SDS-PAGE. Ni-NTA chromatography

Formulation:
The protein was lyophilized from a solution containing 1X PBS, pH 8.0.

Reconstitution:
It is recommended to reconstitute the lyophilized protein in sterile H₂O to a concentration not less than 100 μg/mL and incubate the stock solution for at least 20 min to ensure sufficient re-dissolved.

Storage:
Lyophilized protein should be stored at -20°C. Upon reconstitution, protein aliquots should be stored at -20°C or -80°C.

Note:
Please use within one month after protein reconstitution.

Data Sheet