Characterization of anti-4.1G antibody AbG.

To test a possible cross-hybridization between AbHP and AbG, HeLa whole-cell extract and red blood cell membrane (RBC mbr) samples were immunoblotted with AbHP (left panel). The blot was then stripped and probed with AbG (right panel). Red blood cell membrane proteins served as negative control for both antibodies. AbHP revealed bands around 98 and 54 to 59 kDa, comparable in size to 4.1R isoforms found in nuclear matrix.7 AbG revealed a high-molecular–weight isoform of approximately 160 kDa, similar to a full-length 4.1G isoform observed in transfected cells,5 or an endogenous 4.1G isoform found in PC12 cells.26 Other smaller and uncharacterized bands reacted with AbG, but not with AbHP. The band approximately 96 kDa in particular is slightly smaller than the 98-kDa isoform reacting with AbHP.