期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1978
卷号：75
期号：10
页码：4774-4778
DOI：10.1073/pnas.75.10.4774
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Lymphoid cells obtained from the peripheral blood of a patient with heavy chain disease have been established in long-term culture. They continue to produce a protein antigenically identical to the deleted gamma3 heavy chain disease protein found in the patient's serum. The availability of the cell line has made it possible to analyze the mRNA coding for this protein. The primary in vitro translation product is 1500-2000 daltons larger than the polypeptide portion of the cytoplasmic or secreted protein and has methionine at the amino terminus. The mRNA sediments at 15.5 S on sucrose gradients and therefore appears to be smaller than the 17S message coding for normal-sized mouse gamma chains. It contains a base sequence that codes for a hydrophobic amino-terminal peptide not found in the cytoplasmic protein. There was no evidence for the synthesis of translatable light chain message by these cells. The present data suggest that this protein results from a primary somatic genetic event that gave rise to a cell product bearing a normal aminoterminus sensitive to limited proteolytic digestion. The serum protein thus appears to begin in the hinge region but, in fact, contains a normal heavy chain initiation site.
