Material Data Sheet

Protein Fraction I (Ub, E2, E3)

Price: $109.00
Catalog #: F-375

Protein Fraction I (Ub, E2, E3)

$109.00 $429.00
1 mg 5 mg

Also known as: FI

Protein fraction of a cell extract that does not bind to anion exchange resin. Contains ubiquitin and fraction I E2 and E3s enzymes. FI is essentially free of ATP.

Product Information

X mg/ml in 50 mM HEPES pH 8.0.Actual protein concentration will vary with specific lot number. 

Use & Storage


Ideal for demonstrating if FI enzymes are critical for degradation of in vitro
substrates as well as in vitro conjugation activity. Isopeptidase inhibitor (U-201) and a proteasome inhibitor are highly recommended for the efficient accumulation of ubiquitin-protein conjugates. May require FII (F-370) for activity in the presence of proteasome and isopeptidase inhibitors. A typical assay concentration for FI is 0.5-4 mg/ml. [Note: FI may have a cloudy appearance. This is normal.]

Store at -80°C. For best results, aliquot and freeze after first set of experiments to avoid multiple freeze/thaw cycles.



Hersko A., et al. (1982) J. Biol. Chem. 258:8206-8214