Leukotriene A4 Hydrolase, Recombinant, Human (LTA4H)

Leukotrienes are a family of lipid mediators important in a variety of allergic and inflammatory reactions. Synthesized by leukocytes, these molecules are divided into two classes, the spasmogenic cysteinyl leukotrienes and LTB4, a classical chemoattractant (1). Encoded by the LTA4H gene, leukotriene A4 hydrolase catalyzes the conversion of unstable epoxide LTA4 to LTB4, which is the final and committed step in LTB4 biosynthesis. As a bifunctional zinc metalloenzyme, LTA4H also acts as an arginyl aminopeptidase (2). LTA4H is a drug target for anti-inflammation, and for cancer prevention and therapy (1,3). The mature chain of human LTA4H consists of 610 amino acids (residues 2 - 611). It is highly specific for LTA4, which also covalently modifies and inhibits the enzyme. The aminopeptidase activity is enhanced by monovalent anions (1). rhLTA4H corresponds to the mature chain, and is characterized by its arginyl aminopeptidase activity. Source: Recombinant Human Leukotriene A4 Hydrolase encoded by the LTA4H gene (rhLTA4H, residues 1-611, Accession # P09960) was expressed with a C-terminal 10-His tag in Sf 21. , Molecular Mass: The purified rhLTA4H has a N-terminal sequence of P 2 EIVDTCSLA. The 620 amino acid residue rhLTA4H predicts a molecular mass of 70kD and migrates with an apparent molecular mass of approximately 66kD in SDS-PAGE under reducing conditions. Endotoxin Level: < 1EU/ug of the protein as determined by the LAL method. , Activity: Measured by its ability to cleave a fluorogenic peptide substrate, R-AMC. See Activity Assay Protocol on next page for details. The specific activity, measured with 100uM substrate and 0.5ug rhLTA4H in 100ul of 50mM Tris, 150mM NaCl, 10mM CaCl 2, pH 7.5 at RT, is > 40 pmoles/min/ug., , Storage: This protein can be aliquoted and stored under sterile conditions at -20°C in a manual defrost freezer for up to six months without a significant loss of activity.