Fig. 2. Proteolytic processing of Spz 8.19 by active forms of Ea. An immunoblot, using anti-Spz C-terminal specific antiserum, of conditioned cell culture medium from co-expression of Spz 8.19 (40 kDa). While the inactive Ea zymogen had no effect upon the 40 kDa polypeptide, a constitutively active Ea catalytic chain, EaΔn, or Ea in combination with one of two different active forms of Snk, SnkΔn and XaSnk, led to generation of a 12 kDa C-terminal Spz fragment.