Fig. 5. Western blot analysis of myc-tagged MyBP-C and MyBP-H recombinant proteins expressed in COS cells. (A) Cultured cells were transfected with pJDp-expression plasmids containing myc-tagged full-length MyBP-C, C7-10, C10 or C1-9, as described in Fig. 1. Two days after transfection whole cell lysates were prepared. The lysates were then subjected to SDS-PAGE, transferred electrophoretically to nitrocellulose and reacted with anti-c-myc mAb. Mock-transfected COS cell lysate served as a negative control. (B) COS cells were similarly transfected with myc-tagged MyBP-H constructs (full-length MyBP-H, HU, HU1 or H4) and analyzed on western blots with anti-c-myc antibody. (C) Myc-tagged MyBP-H recombinant proteins were further tested with a polyclonal antibody against chicken MyBP-H. A high salt crude extract of chicken skeletal muscle served as a positive control. The numbers to the left of each gel indicate relative molecular weights of a pre-stained protein standard (Life Technologies, Rockville, MD).