Thromb Haemost 1985; 53(03): 377-380
DOI: 10.1055/s-0038-1661318
Original Article
Schattauer GmbH Stuttgart

Effect of Proteolysis on Quantitation of Plasma Fibronectin Concentration by Two Immunoassays (Electroimmunoassay and Immunoturbidimetric Technique)

K Bykowska
The Department of Radiobiology and Health Protection, Institute of Nuclear Chemistry and Technology, Warsaw, Poland
,
Z Wegrzynowicz
The Department of Radiobiology and Health Protection, Institute of Nuclear Chemistry and Technology, Warsaw, Poland
,
S Lopaciuk
The Department of Radiobiology and Health Protection, Institute of Nuclear Chemistry and Technology, Warsaw, Poland
,
M Kopeć
1   The Laboratory of Clinical Biochemistry, Institute of Haematology, Warsaw, Poland
› Author Affiliations
Further Information

Publication History

Received 19 September 1984

Accepted 20 March 1985

Publication Date:
21 August 2018 (online)

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Summary

Quantitation of fibronectin (FN) concentration is strongly influenced by FN fragmentation with trypsin, kallikrein and plasmin. Digestion by trypsin and kallikrein leads to a progressive decline in FN detectability by the immunoturbidimetric technique to zero values but is associated with an increase in the height of rockets in the Laurell’s electroimmunoassay. Plasmin mediated FN fragmentation induces a strong overestimation of the FN content by the electroimmunoassay and, at very high enzyme concentrations, provokes an underestimation of FN by the immunoturbidimetric technique. The decline in FN reactivity in the immunoturbidimetric assay coincides with the disappearance of heavy fractions migrating only slightly faster than native FN in SDS-PAGE. The increase in the height of rockets in the electroimmunoassay is the highest when fractions of intermediate rate of migration prevail in the SDS-PAGE pattern. Concomitant use of these two immunoassays can distinguish native FN from its degraded form and may possibly provide a partial explanation for discrepancies in published studies on the concentration of circulating FN in various pathological states.