title: Disulfide linkages between antigen-binding receptors on chicken B-lymphocytes.
abstract: Membrane immunoglobulin receptors on chicken B-cells have been shown to display a heterogeneity with respect to interchain disulfide linkages. One fraction of the surface Ig (sIg) appears to display the traditional H2-L2 linkage. We also present evidence that this Ig is covalently bound via a disulfide linkage to actin. In this instance, the isolated Ig heavy chain, after reduction, has a mol. wt of 80 K. Perhaps more significantly, we show that another fraction of the sIg exists in a highly aggregated from that is stabilized by disulfide linkages. In contrast to the sIg found in the H2-L2 configuration, there is no evidence of actin within the aggregates and the sIg heavy chains isolated from these aggregates display a slightly faster mobility on SDS-PAGE under reducing conditions, running at about 77K. Furthermore, it appears that the Ig within the large aggregates may have a higher avidity with respect to antigen binding, and so this Ig structure may be the more relevant to antigen-induced receptor-mediated signaling in the B-cell.
authors.forename: A J
authors.initials: AJ
authors.lastname: Rosenspire
authors.forename: M S
authors.initials: MS
authors.lastname: Lee
authors.forename: S V
authors.initials: SV
authors.lastname: Pollak
authors.forename: Y S
authors.initials: YS
authors.lastname: Choi
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002645:Chickens; D002846:Chromatography, Affinity; D004220:Disulfides / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D007143:Immunoglobulin Heavy Chains / Q000032:analysis; D008970:Molecular Weight; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism*; D013154:Spleen / Q000276:immunology
chemical_list: D004220:Disulfides; D007143:Immunoglobulin Heavy Chains; D011947:Receptors, Antigen, B-Cell