Purification procedure and monoclonal antibodies: Two instruments for research on vertebrate porins

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.