The amino acid sequence of rabbit J chain in secretory immunoglobulin A

Biochem J. 1990 Nov 1;271(3):641-7. doi: 10.1042/bj2710641.


The primary structure of rabbit J chain, which occurs covalently bound to secretory IgA, was determined. J chain was isolated in its S-carboxymethylated form, in one step, by SDS/PAGE followed by electro-elution; 5 nmol of protein (approx. 75 micrograms), in all, was necessary for the determination of the complete sequence by the 'shot-gun' microsquencing technique; with the use of several site-specific endoproteinases, the various digests of S-carboxymethylated J chain were separated by micro-bore reverse-phase h.p.l.c. and the partial N-terminal sequences of all peptides were analysed. From the sequence alignment, gaps were filled by further extensive sequencing of the relevant overlapping fragments isolated from selected digests. Rabbit J chain comprises 136 amino acid residues, out of which eight are conserved cysteine residues, and is more closely similar to the human sequence (73.5% identify) than to the mouse sequence (68% identity). There is one unique glycosylation site at asparagine-48.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Asparagine / metabolism
  • Carbohydrate Metabolism
  • Chromatography, High Pressure Liquid / methods
  • Electrophoresis, Polyacrylamide Gel / methods
  • Humans
  • Immunoglobulin A, Secretory / chemistry*
  • Immunoglobulin J-Chains / chemistry*
  • Immunoglobulin J-Chains / isolation & purification
  • Mice
  • Microchemistry / methods
  • Molecular Sequence Data
  • Peptide Fragments / metabolism
  • Peptide Hydrolases / metabolism
  • Rabbits
  • Sequence Homology, Nucleic Acid
  • Sodium Dodecyl Sulfate


  • Immunoglobulin A, Secretory
  • Immunoglobulin J-Chains
  • Peptide Fragments
  • Sodium Dodecyl Sulfate
  • Asparagine
  • Peptide Hydrolases