On Western blots of skeletal muscle preparations of different vertebrate cl
asses, four monoclonal anti-human type 1 porin antibodies recognize one sin
gle band of either 30.5 or 31 kDa, respectively. To confirm that it is euka
ryotic porin which is labeled by the antibodies, we used a purification pro
cedure developed for human type 1 porin for porins from skeletal muscle of
shark, frog, and turkey. Applied to different mammalian species and tissues
, this procedure exclusively provides type 1 porin. However, applied to sha
rk skeletal muscle, it provides two porin isotypes in nearly equal amounts.
In the case of frog skeletal muscle, the procedure provides mainly type 2
porin and a lower amount of type 1 porin. Applied to turkey skeletal muscle
, the method provides exclusively type 2 porin. As demonstrated by two-dime
nsional Western blots, both shark and frog porin isotypes and the turkey ty
pe 2 porin are recognized by our antibodies. Furthermore, we elucidated the
entire mine acid sequence of frog type 2 porin. (C) 1999 Academic Press.