Abstract | BACKGROUND: It has been found that the immunoglobulin A1-binding protein (IgA1-BP) can be separated from human serum using an asialo-, agalacto-IgA1 (aglyco-IgA1)-Sepharose column (13). As the IgA content in IgA1-BP was significantly higher in IgA nephropathy patients than that in other nephropathy patients, the relationship between IgA in IgA1-BP and glomerular deposited IgA was predicted. METHODS: RESULTS: A rapid separation method of IgA1-BP from serum by the aglyco-IgA1-HPLC column was developed and this column confirmed the reproduction of the IgA1-BP separation. The following similarities between IgA in IgA1-BP and glomerular deposited IgA were detected. A major portion of IgA in IgA1-BP was the IgA1 subclass. The IgA was rich in medium-size IgA and in the jacalin-high-affinity IgA1 fraction. The IgA showed a statistically significant lower kappa/lambda ratio in its light-chain composition than that of serum IgA, i.e. abundance in IgA bearing the lambda light chain. Other immunoglobulin classes ( IgG and IgM) in IgA1-BP also exhibited a significantly low kappa/lambda ratio. CONCLUSIONS: In this experiment, preferential bindings of the IgA1 subclass, the medium-size IgA and the IgA with the lambda light chain to the aglyco-IgA1-column were observed. Based on previous reports concerning aglyco-IgA1 self-aggregation, the interaction of aglyco-IgA1 with matrix proteins and the rat glomerular deposition of artificially deglycosylated IgA1, IgA in IgA1-BP is thought to be partially the same molecule as the IgA deposited on the mesangial matrix in the IgA nephropathy patient.
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Authors | Toru Takatani, Hitoo Iwase, Akihiko Itoh, Ikuko Nakamura, Miyuki Hayashi, Hisato Sakamoto, Kouju Kamata, Yutaka Kobayashi, Yoshiyuki Hiki, Makito Okamoto, Masaaki Higashihara |
Journal | Journal of nephrology
(J Nephrol)
2004 Sep-Oct
Vol. 17
Issue 5
Pg. 679-86
ISSN: 1121-8428 [Print] Italy |
PMID | 15593035
(Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Immunoglobulin A
- Lymphokines
- Plant Lectins
- immunoglobulin-binding factors
- jacalin
- Sepharose
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Topics |
- Chemical Fractionation
- Chromatography, Affinity
- Chromatography, High Pressure Liquid
(methods)
- Enzyme-Linked Immunosorbent Assay
- Glomerulonephritis, IGA
(blood, immunology)
- Humans
- Immunoglobulin A
(blood, chemistry, metabolism)
- Kidney Glomerulus
(immunology)
- Lymphokines
(blood, chemistry, isolation & purification)
- Plant Lectins
- Sepharose
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