General description

Peptidyl Arginine Deiminases (PADs) perform post-translational deiminations of proteins. PADs are calcium-dependent enzymes that catalyze the conversion of L-arginine residues to L-citrulline. The reaction catalyzed is as follows: Protein--[L-arginine] + H₂O+Ca⁺²→Protein--[L-citrulline]+ NH₄ This deimination provides another level of regulating protein function.There are five mammalian PADs sub-types, which differ in substrate specificity and tissue distribution. PAD enzymes are highly homologous, with 50–60% sequence similarity. PADenzymes play important roles in gene regulation by citrullination of arginine residues on histones H3, H2A, and H4. Overexpression of these enzymes has been found in several diseases such as rheumatoid arthritis, Alzheimer′s disease, multiple sclerosis, lupus, Parkinson′s disease, and cancer. PAD2 is widely expressed in the brain, secretory glands, and skeletal muscles. The enzyme was found to be responsible for hyper-citrullination of myelin basic protein, which is suspected to lead to multiple sclerosis. The product is supplied in 20 mM Tris, pH 7.5, 200 mM NaCl, 10% (w/v) glycerol, 10 mM 2-mercaptoethanol, 1 mM EDTA, 1 mM DTT, 10 mM CaCl₂, 10 mM arginine, 30 mM maltose, and 0.6 mg/ml dodecyl−β-D-maltoside. Enzymatic activity: Activity is measured by a colorimetric method with the synthetic substrate benzoyl arginine ethyl ester (BAEE).

Physical form

Supplied as a buffered aqueous solution containing Trizma, NaCl, glycerol, mercaptoethanol, EDTA, DTT, CaCl₂, arginine, maltose, and dodecyl-β-D-maltoside.

Preparation Note

Contains a maltose-binding protein fusion tag.

Unit Definition

One unit will produce 1.0 µmole of N-a-benzoylcitrulline ethyl ester from BAEE per hr at 55 °C at pH 7.2.