Membrane-bound and secreted IgA contain structurally different alpha-chains

UMMS Affiliation

Department of Molecular Genetics and Microbiology

Publication Date


Document Type



Animals; Antibody-Producing Cells; B-Lymphocytes; Cell Line; Chemistry; Electrophoresis, Polyacrylamide Gel; Goats; Immunoglobulin A; *Immunoglobulin Heavy Chains; *Immunoglobulin alpha-Chains; Lymphoma; Mice; Mice, Inbred Strains; Receptors, Antigen, B-Cell; Tunicamycin


Life Sciences | Medicine and Health Sciences | Women's Studies


Three different forms of alpha-chains are synthesized by BF0.3 and 615.2, two cloned cell lines derived from the murine B lymphoma 1.29. The three forms of alpha-chains differ in size, pI, cellular location, and rate of turnover. They were identified by means of lactoperoxidase-catalyzed radioiodination, internal 14C or 35S labeling, and immunofluorescence techniques as membrane-bound(alpha m), secreted (alpha s), and intracellular (alpha ic) proteins. Comparison of immunoglobulin products of the two lymphoma lines with those of a hybridoma cell line, Id 150, which secretes IgA of the 1.29 idiotype but lacks membrane IgA, confirmed the assignments of alpha m, alpha s, and alpha ic. Results of biosynthetic labeling of BF0.3, 615.2, and Id 150 in the presence and absence of tunicamycin suggest that the difference in m.w. and charge observed between alpha m and alpha s can be attributed to differences in primary amino acid structure rather than different degrees of glycosylation.


J Immunol. 1982 Feb;128(2):712-6.

Journal/Book/Conference Title

Journal of immunology (Baltimore, Md. : 1950)

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Link to article in PubMed

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