Alterations in iodinated cell surface proteins during myogenesis.

Lactoperoxidase catalysed iodination was used to label surface proteins of chick embryo muscle cells during myogenesis. Both quantitative and qualitative changes were observed between 125I-labelled surface proteins of pre-fusion, mid-fusion, and post-fusion cells. Significantly, two bands at 245,000 molecular weight were present at pre-fusion but were observed as a single band at mid- and post-fusion. Radioactivity in this band increased selectively at post-fusion with a concomitant increase in lower molecular weight labelled proteins.