The charge-heterogeneity of human fibrinogen as investigated by 2D electrophoresis

The charge-heterogeneity of human plasma fibrinogen subunit chains was char acterized by two-dimensional electrophoresis (2DE). Western blotting with a ntibodies specific for the gamma -chain demonstrated that the gamma -chains focus at varying isoelectric points (pI). This microheterogeneity was also observed in fibrinogen secreted from hepatocytic cells and in recombinant fibrinogen expressed in Chinese hamster ovary (CHO) cells. Further, covalen t yy-dimerization by FXIIIa was not influenced by the charge-heterogeneity, and removal of the carbohydrate did not reduce the number of gamma -chain pi variants. These observations suggest that the microheterogeneity of the gamma -chain is a multifactorial phenomenon that is not due to physiologic modification of the glycoprotein in circulation. (C) 2000 Elsevier Science Ltd. All rights reserved.