Primary Structure of Human J Chain: Alignment of Peptides from Chemical and Enzymic Hydrolyses

Academic Article


  • The primary structure of the J chain from a human Waldenstr√∂ms IgM protein has been determined using a combination of automated and conventional Edman degradative procedures. Eighty-five percent of the sequence was established with peptides isolated from tryptic digests of carboxyamidomethylated and citraconylated J chain, many of which were sequenced completely. Alignment of the tryptic fragments was achieved with peptides generated by chymotrypsin and limited acid hydrolyses. The J chain consists of 129 amino acids and a single oligosaccharide structure linked to asparagine at position 43 of the sequence. The molecular weight, including 7.5% carbohydrate by weight, is 16 422. The location and arrangement of three half-cystines could be deduced from previous studies, whereas the pairing of the remaining five disulfide bonds still needs to be clarified. ¬© 1977, American Chemical Society. All rights reserved.
  • Authors

    Published In

  • Biochemistry  Journal
  • Digital Object Identifier (doi)

    Author List

  • Mole JE; Bhown AS; Bennett JC
  • Start Page

  • 3507
  • End Page

  • 3513
  • Volume

  • 16
  • Issue

  • 16