Mouse Meprin  beta Subunit/MEP1B Alexa Fluor™ Plus 555-conjugated Antibody

Meprins are multimeric proteases composed of alpha and beta subunits, which are members of the astacin family of zinc endopeptidases (1, 2). Both subunits form disulfide-linked homo- or heterooligomers, which are also referred to as meprin A (composed of alpha subunits with or without beta subunits) and meprin B (composed of beta subunits only) (3). Although the two subunits share 42% identity in their amino acid sequence, they differ significantly in their oligomeric structure, post-translational processing and subsequently cellular location, and substrate and peptide bond specificity (4). The 704 amino acid sequence of mouse meprin beta subunit precursor consists of a signal peptide (residues 1-20), a pro region (residues 21-62), and a mature chain (residues 63-704) containing following domains, catalytic (residues 63-260), MAM (residues 261-430), MATH (residues 431-586), EGF-like (residues 607-647), transmembrane (residues 655-678), and cytoplasmic (residues 679-704). The pro enzyme terminating at residue 594 was expressed and the secreted protein purified from conditioned medium. The amino acid sequence has Ile and Val at position 75 and 432 instead of Thr and Ile, respectively. After trypsin treatment, the activated enzyme cleaved a flurogenic peptide, which contains Asp and Glu, the preferred residues found in the P1’ and P1 sites (3).