Interchain and Intrachain Disulfide Bridges of a Human Immunoglobulin M: Detection of a Unique Fragment
Abstract
Studies of the amino acid sequences around half-cystine residues in an immunoglobulin M have revealed an unexpectedly high number. At least 14 different sequences were found in the μ chain (VHIII subclass). Four of these were involved in interchain disulfide bridges and at least 10 in intrachain bridges. Five came from the κ chain (κIII subclass, Inv b). Several others, although having a high degree of homology, were not identical with those of either the μ or κ chains. These results support the concept of an additional fragment in γM molecules, although its function and localization remain to be determined.
Footnotes
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↵ * Present address: Laboratory of Immunochemistry, Research Institute on Blood Diseases, Hopital Saint-Louis, Paris 10e, France.
