Characterization of amyloidogenic immunoglobulin light chains directly from serum by on-line immunoaffinity isolation

H. Robert Bergen, Roshini S. Abraham, Kenneth L. Johnson, Arthur R. Bradwell, Stephen Naylor

Research output: Contribution to journalArticle

19 Scopus citations

Abstract

Primary systemic amyloidosis (AL) is characterized by the overproduction of immunoglobulin light chain proteins by a monoclonal, terminally differentiated B-lymphocyte or plasma cell clone. The free immunoglobulin light chains are deposited in an abnormal conformation as amyloid in a variety of organs in the body. The mechanism of amyloid formation is not well understood, but appears to be associated with some form of cleavage of the immunoglobulin light chain with subsequent aggregate formation. In an attempt to characterize the structure of amyloid-forming light chain proteins we developed an on-line immunoaffinity purification and subsequent characterization of free κ and free λ immunoglobulin light chains by electrospray ionization mass spectrometry. The methodology is totally automated and requires 20 μL of serum. Mass spectral analysis of Bence Jones proteins under non-denaturing conditions was also utilized to examine the tertiary and quaternary structure of light chain proteins and clearly shows covalent dimer formation of lambda type light chain. This type of on-line assay may prove helpful in elucidating distinguishing features capable of discriminating AL from benign monoclonal gammopathies of undetermined significance as well as diagnosing AL.

Original languageEnglish (US)
Pages (from-to)191-201
Number of pages11
JournalBiomedical Chromatography
Volume18
Issue number3
DOIs
StatePublished - Apr 1 2004

    Fingerprint

Keywords

  • Desalting trap
  • ESI MS
  • Immunoaffinity cartridge

ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry
  • Molecular Biology
  • Pharmacology
  • Drug Discovery
  • Clinical Biochemistry

Cite this