Invitrogen™ EK-Away™ Resin

Catalog No.	Quantity
R18001	7.5 mL

Catalog No. R18001 Supplier Invitrogen™ Supplier No. R18001

Description

Includes

EK-Away is provided as a 50% ethanol slurry; 10X binding and 10X stripping buffers are included; 7.5mL resin will remove 250 units of enterokinase; 30mL will remove 1000 units of EKMax.

Specifically designed for removal of EKMaxor other enterokinase enzymes following cleavage of proteins containing the enterokinase cleavage site

• The resin is conjugated with soybean trypsin inhibitor, which has a high affinity and binding capacity for enterokinase
• The enzyme catalytic site binds this agarose-based resin for simple batch or column-bound removal of EKMaxor other enterokinase preparations

GST-Tagged Protein Purification, His-Tagged Protein Purification, Protein and Peptide Purification, Protein Sample Preparation and Protein Purification, Proteins, Expression, Isolation and Analysis

Specifications

• Content And Storage: EK-Away™ is provided as a 50% ethanol slurry and should be stored at +4°C. 10X binding and 10X stripping buffers are included. 7.5 ml resin will remove 250 units of enterokinase; 30 ml will remove 1000 units of EKMax™. All reagents are guaranteed stable for 6 months when stored properly.
• Form: Liquid Suspension
• Product Line: EK-Away
• Quantity: 7.5 mL
• Type: Resin
• Stationary Phase: Enterokinase
• Column Type: Affinity

Frequently Asked Questions (FAQs)

What is the molecular weight of the EKMax enterokinase enzyme?

EKMax enterokinase is a clone of the catalytic subunit of enterokinase expressed in the yeast Pichia pastoris. The calculated molecular weight of the protein is 26.3 kDa, but it contains three sites for asparagine-linked glycosylation. The apparent molecular weight of 43 kDa is consistent with previous observations (LaVallie et al., 1993) and is assumed to be because of N-linked glycosylation.
Reference: LaVallie, E.R., Rehemtulla, A., Racie, L.A.,Diblasio, E.A., Ferenz, C., Grant, K.L. Light, A., and McCoy, J.M. (1993). Cloning and functional expression of a cDNA encoding the catalytic subunit of bovine enterokinase. J.Biol.Chem. 268, 23311-23317.

Will DTT, Triton X-100 detergent, Tween 20 detergent, Thesit, calcium chloride, sodium chloride, or SDS affect the efficiency of Enterokinase (EKMax) enzyme cleavage?

Enterokinase is active in buffers containing up to 1 mM DTT, 0.1% Triton X-100 detergent, 0.1% Tween 20 detergent, and 0.1% Thesit. It is recommended to have 10mM Tris pH 8.0 and 10 mM calcium chloride in the buffer. Enterokinase is inhibited by sodium chloride and SDS.

Should Enterokinase be resuspended in a buffer containing 50% glycerol to protect the protein from freeze/thaw cycles?

Freeze thaw has a minimal effect on the activity of Enterokinase. The addition of glycerol is not necessary but can make handling of the enzyme easier.

How specific is cleavage by EKMax Enterokinase? Are there any alternate cleavage sites for the enzyme?

Enterokinase cleaves after the sequence (Asp)4-Lys.

It has been proposed that the active center of enterokinase possesses a distinctive cationic subsite that binds -(Asp)4. Enterokinase is highly specific and tolerates very few changes to its recognition site. If the ionic charge of the recognition site is preserved, enterokinase will recognize the site, but the rate of hydrolysis of the peptide bond will be reduced (Light and Janska, 1989). The four aspartyl residues act as a signal for enterokinase cleavage. It has been reported that with only three aspartyl residues the rate of hydrolysis is reduced. Two aspartyl residues preceding the lysyl residue are the minimum number of acidic residues needed to maintain specificity (Maroux et al., 1971). Non-specific cleavage by enterokinase may occur in the cases described above, but this is usually alleviated by reducing the amount of enzyme used.

Safety and Handling

WARNING: Cancer - www.P65Warnings.ca.gov

For Research Use Only. Not for use in diagnostic procedures.