Amino acid sequence of the first constant region domain and the hinge region of the delta heavy chain of human IgD.

• DOI: 10.1073/pnas.78.10.6168
• Publication Date: 2006-05-31T08:29:08Z
• Authors: F W Putnam; N Takahashi; D Tetaert; B Debuire; L C Lin
• Keywords: Immunoglobulin D; Homology; Sequence (biology)

We have determined the amino acid sequence of first constant (C) region domain (C delta 1) and hinge heavy chain human IgD WAH also adjacent COOH-terminal portion variable (V) region, including JH region. Together with Fc fragment already reported, this establishes complete C confirms presence three domains in IgD. Although CH1 five classes chains expected degree homology (approximately 30%), 1 mouse is less than that exhibited by other pairs chains. The has an unusual structure; NH2-terminal half four (or five) GalN oligosaccharides attached, whereas lacks carbohydrate, dissimilar sequence, a high charge. A computer search verified GalN-rich segment identity middle mu 2 high-charge related to same sequence. propose two segments common evolutionary origin arose duplication independent mutation exon derived from ancestral gene for domain.