Liquid. In sterile-filtered 150 mM NaCl, 25 mM HEPES, 1 mM DTT, 20% glycerol, pH 8.0. AVOID FREEZE/THAW CYCLES. Recombinant human HtrA2/Omi (amino acids 134-458) fused at the C-terminus to a 6X His•Tag^® sequence and expressed in E. coli. HtrA2/Omi is a mitochondrial trypsin-like serine protease that is processed to expose an amino-terminal Reaper-like motif similar to SMAC/Diablo. It is released from the mitochondria in response to apoptotic stimuli and can interact with the BIR2 or BIR3 domains of XIAP to reverse caspase inhibition. The specificity of the protease activity has not been determined and there are currently no identified endogenous substrates. Biological activity: Reversal of XIAP-BIR2-mediated caspase-7 inhibition (50%) = 0.2-1.5 µM as determined by an increase in the rate of DEVD-AFC cleavage by 2 ng caspase-7 in the presence of XIAP-BIR2. Protease activity: 0.2-1.0 nmol HtrA2/0mi will clease ~50% OF 1 µg b-casein at 37°C for 2 h as monitored by SDS-PAGE. Protease activity: 0.2-1.0 nmol HtrA2/Omi will cleave ~50% of 1 µg b-casein at 37°C for 2 h as monitored by SDS-PAGE.. Purity: ≥85% by SDS-PAGE.

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