Mouse Spinesin Alexa Fluor™ Plus 488‑conjugated Antibody

Spinesin, encoded by the TMPRSS5 gene, is a new member of type II transmembrane serine proteases (TTSPs) (1). Mouse Spinesin contains the following structural domains: a short N-terminal cytoplasmic tail, a transmembrane domain, a stem region and a serine protease domain (2). The domain structure of Spinesin is common to other TTSPs, many of which have additional domains. The stem region of Spinesin contains a scavenger receptor-like domain. There could be 4 types of transcripts due to alternative splicing (3). Type 4 predicts 10 extra amino acids at the N-terminus as compared to type 3. The ectodomain corresponding to type 3 (residues 61‑445) or  type 4 (residues 71‑455) was expressed and purified as a single chain pro-enzyme. By SDS-PAGE, the pro-enzyme migrates as multiple forms, possibly due to differential glycosylation. The pro-enzyme can be activated by trypsin treatment. The resulting enzyme is active and its activity is measured as described above. The activated enzyme is a disulfide bond-linked dimer.