title: A protein binding specifically to the IgG2b switch region.
abstract: The Abelson-virus-transformed mouse pre-B-cell line 18-81 switches almost exclusively from mu to gamma 2b. From nuclear extracts of this cell line, we have isolated a factor that specifically binds to S gamma 2b. After an eight-step purification scheme, in which different types of DNA-affinity chromatography were used as key elements, we obtained a preparation with two narrowly spaced bands at approximately 69 kD on a silver-stained SDS gel. Binding specificity of main-peak fractions of affinity-purified proteins was analyzed by gel shift assays, in which S gamma 2b, but not S mu, competes. The results are consistent with this factor being part of the switch recombinase.
authors.affiliation: Department of Microbiology and Immunology, University of California, San Francisco 94143-0670, USA.
authors.forename: H
authors.initials: H
authors.lastname: Völk
authors.forename: M
authors.initials: M
authors.lastname: Wabl
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D001345:Autoradiography; D001483:Base Sequence; D002461:Cell Line, Transformed; D002472:Cell Transformation, Viral; D002846:Chromatography, Affinity; D018983:DNA Footprinting; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D007074:Immunoglobulin G / Q000235:genetics*; D007134:Immunoglobulin Switch Region; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011995:Recombination, Genetic; D012091:Repetitive Sequences, Nucleic Acid
chemical_list: D004268:DNA-Binding Proteins; D007074:Immunoglobulin G