The complete amino-acid sequence of the heavy chain of the human myeloma protein WIE, an immunoglobulin D.

The human myeloma protein WIE is a lambda-type immunoglobulin D; the amino-acid sequence of its Fc part and aminoethylated heavy chain was completely determined. The VH-part (subgroup III) begins N-terminally with 5-oxoproline, and it contains a long, unique CDR3 region. Since the constant part differs from known delta chains by one amino-acid substitution in the hinge region, IgD WIE probably represents an allotypic variant. As in other protein delta chains, O-glycosylations are confined to the hinge region. Furthermore, the ratios of N-glycosylations at the three positions are identical in IgD WAH [Takahashi, N. et al. (1984) J. Chromatogr. 317, 11-26.] and IgD WIE (100%, 50%, 100%). From the most conserved constant domain, C delta 3, a three-dimensional model was constructed to clarify the role of its delta-specific substitutions and glycosylation.