Purification and characterization of Ki antigen and detection of anti-Ki antibody by enzyme-linked immunosorbent assay in patients with systemic lupus erythematosus.

Abstract

Ki antigen from rabbit thymus extract was purified by ammonium sulfate precipitation, anti-Ki affinity chromatography, and high pressure liquid chromatography gel filtration. The purified Ki antigen gave a single polypeptide with an MW of 32,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and it specifically reacted with anti-Ki antibody by immunoblotting. The isoelectric point of the Ki antigen was found by isoelectric focusing to be 4.3. An enzyme-linked immunosorbent assay using the purified Ki antigen was established, and the clinical significance of the anti-Ki antibody in systemic lupus erythematosus (SLE) was studied. Thirty of 140 patients with SLE (21.4%) had anti-Ki antibody by enzyme-linked immunosorbent assay, whereas 11 (7.9%) were positive by double immunodiffusion. Analysis of clinical and serologic data on patients with SLE suggested a higher prevalence of central nervous system involvement in patients with anti-Ki antibody.

• Authors: M Sakamoto, Y Takasaki, K Yamanaka, A Kodama, H Hashimoto, S Hirose
• Journal: Arthritis and rheumatism (Arthritis Rheum) Vol. 32 Issue 12 Pg. 1554-62 (Dec 1989) ISSN: 0004-3591 [Print] United States
• PMID: 2597210 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies
• Nuclear Proteins
• Peptides

Topics

• Antibodies (analysis)
• Dermatomyositis (immunology)
• Enzyme-Linked Immunosorbent Assay
• Humans
• Isoelectric Focusing
• Lupus Erythematosus, Systemic (complications, immunology)
• Mixed Connective Tissue Disease (immunology)
• Myositis (immunology)
• Nuclear Proteins (analysis, immunology, isolation & purification)
• Peptides (analysis)