To our knowledge, so far the only reliable commercial antibody for (pro)matriptase-2 determination in vivo. Highly unspecific, it detects many bands, but comparison of WT and mask mice clearly shows that matriptase-2 is there, at about 125 kDa (Frýdlová J et al., Effect of Erythropoietin, Iron Deficiency and Iron Overload on Liver Matriptase-2 (TMPRSS6) Protein Content in Mice and Rats. PLoS One. 2016 Feb4;11(2):e0148540).
With AB 56182, full-length matriptase-2 can be detected both in mice and rats. Actually, rat seems to be the animal of choice if one wants to upregulate TMPRSS6 by iron deficiency (Gurieva I et al., Erythropoietin administration increases splenic erythroferrone protein content and liver TMPRSS6 protein content in rats. Blood Cells Mol Dis. 2017 Feb28;64:1-7). One should always bear in mind the fact that the detected, 125 kDa full-length form of matriptase-2 very probably represents the inactive proenzyme, which is activated by proteolytic cleavage – a nice analogy is the activation of prothrombin to thrombin. To the best of our knowledge,nobody has seen the active, 26 kDa form of matriptase-2 in vivo.
There are 7 predicted glycosylation sites according to UNIPROT Q9DBI0; PNGase F treatment indeed shifts the detected band from opproximately 125 kDa to approximatly 100 kDa – see figure.
Lanes 1 and 2 are without PNGase, lane 3 is with PNGase F (New England Biolabs).