Two-dimensional gel electrophoresis of 125I-labeled surface proteins of human fibroblasts.

Human fibroblasts were labeled by the 125I-lactoperoxidase technique and the sodium dodecyl sulfate soluble proteins examined by two-dimensional gel electrophoresis to determine the charge heterogeneity of the surface proteins and test for differences in surface proteins in several hereditary disorders. Approximately 80 polypeptides were observed. Those below 65 000 daltons tended to occur as single spots, while those of higher molecular weight were often present as a series of polypeptides of similar molecular weight (charge isomers). The possible role of these proteins in cell-cell recognition is discussed.