Recombinant Protein. Mouse isthmin-1 aa 30-461 is fused at the C-terminus to a His-tag. .Source HEK 293 cells. Endotoxin content <0.01EU/µg purified protein LAL test.. Lyophilized. Contains PBS. Purity >95% SDS-PAGE. Isthmin-1 ISM1 was first identified as a gene expressed in the Xenopus midbrain hind brain organizer called isthmus, with a proposed role during early brain development. Isthmin-1 encodes a predicted ~50-kDa protein containing a signal peptide, a thrombospondin domain and an adhesion-associated domain. Isthmin-1 is important for embryonic and postnatal development. Growing evidence has shown that aberrant expression of Isthmin-1 can also affect the biological behavior of cancer. The Ism1 gene is conserved in mice and humans. A recent study showed that Ism1 is an adipokine that induces glucose uptake in human and mouse adipocytes.