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：1974
卷号：71
期号：3
页码：974-978
DOI：10.1073/pnas.71.3.974
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Protein Def is a human alpha chain disease protein related to [α]1 immunoglobulin heavy chain. The molecular weight of the polypeptide portion of the monomeric molecule is 29,300, which is a little greater than half of a normal [α]1 chain. The NH2-terminal of the polypeptide is heterogenous and, after a short segment corresponding to the variable region, displays a gap which comprises the CH1 constant domain. Normal synthesis resumes at a valine residue in the hinge region just before a segment which contains a partially duplicated fragment and the interheavy disulfide bonds. From there on, the molecule is apparently normal. Protein Def is therefore synthesized as an internally deleted [α]1 heavy chain, followed by postsynthetic amino-terminal proteolysis. It is postulated that codon(s) specifying valine at the hinge region may be a recognition site for reinitiating synthesis after internal gaps equivalent to position 216 in gamma chain disease proteins.
