Wolfenstein-Todel C, Mihaesco E, Frangione B
Proc Natl Acad Sci U S A. 1974 Mar;71(3):974-8. doi: 10.1073/pnas.71.3.974.
Protein Def is a human alpha chain disease protein related to alpha1 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 alpha1 chain. The NH(2)-terminal of the polypeptide is heterogenous and, after a short segment corresponding to the variable region, displays a gap which comprises the C(H)1 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 alpha1 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.
蛋白质Def是一种与α1免疫球蛋白重链相关的人类α链疾病蛋白。单体分子多肽部分的分子量为29,300，略大于正常α1链的一半。多肽的NH(2)末端是异质的，在对应于可变区的短片段之后，存在一个缺口，该缺口包含C(H)1恒定结构域。正常合成在铰链区的一个缬氨酸残基处重新开始，就在一个包含部分重复片段和重链间二硫键的片段之前。从那里开始，分子显然是正常的。因此，蛋白质Def作为内部缺失的α1重链合成，随后进行合成后氨基末端蛋白水解。据推测，铰链区指定缬氨酸的密码子可能是在相当于γ链疾病蛋白中第216位的内部缺口后重新启动合成的识别位点。
