AK/PAK2 (2 Units)
Source: Bovine kidney.
Purity: > 90% by SDS-PAGE, apparent Mr ~ 36-kDa.
Supplied: 100 ng (~ 2 units) in 20 μl 50 mM Tris-HCl pH 7.0 buffer containing 14 mM β-mercaptoethanol, 0.03% Brij-35. 1 mM benzamidine, 0.1 mM phenylmethanesulfonyl fluoride, 1 mM EDTA and 65% ethyleneglycol.
Activity: ~ 17,000 units/mg with myelin basic protein (MBP) as substrate. One unit of AK is the amount of the enzyme that incorporates 1 nmol of phosphate into MBP per min. Maintain preparations in aliquots at -70° C. Avoid repeated thawing.
Synonyms: Auto-Activated Protein Kinase; Autophosphorylation-Activated Protein Kinase; Catalytic Domain of PAK2; Catalytic Domain of p21-Activated Protein Kinase.
Background: The catalytic domain of PAK2 was originally isolated as a relatively rare auto-activated protein kinase (AK), so termed because the purified enzyme underwent rapid autophosphorylation and concomitant 15-30-fold activation. Subsequent discovery of the PAK family of enzymes and amino sequencing of AK revealed that AK was equivalent to the catalytic domain of PAK2.
Unlike the reported activity of native PAK2, AK does not bind nor is it stimulated by the p21-GTPases Cdc42 (GLO128-005, GLO128-025, GLO128-050) and Rac. AK is a physiologically relevant form of PAK2. It is produced from the native enzyme via a caspase-dependent pathway in cells undergoing apoptosis.