Measurement of Elastin Peptides in Urine by Enzyme-Linked Immunosorbent Assay

Comparison of Determinations of Elastin Peptides Levels Using Different Antibodies

Abstract

Elastin peptides (α-elastin and elastase-solubilized elastin Peptide) were prenared from insoluble elastin extracted from normal human aorta. Rabbits were immunized with these elastin peptides. We obtained two antibodies, one each to a -elastin and elastase-solubilized elastin peptide. Using these antibodies, an enzyme immunoassay system for the measurement of elastin peptide was devised, and the competitive binding curve obtained with its use was found to be similar to that obtained for radioimmunoassay. Anti-a-elastin antibody recoanized larger and hydrophobic peptides, whereas anti-elastase-solubilized elastin peptide antibody (anti-elastin peptide antibody) recognized smaller and hydrophilic peptides. The enzymelinked immunosorbent assay (ELISA) using anti-α-elastin antibody was found to be superior to that using anti-elastin peptide antibody for measurement of urinary elastin peptides. The urinar excretion of elastin peptide recognized by anti-α-elastin antibody reflected decree of smokina: the content of elastin peptide in the urine of light smokers (39±22 ng/mg creatinine) was sianificantly less than that in the urine of heavy smokers (188±24 ng/mg creatinine). However, the level of elastin peptide in the urine of light smokers (8.30±0.9μg/mg creatinine) as measured using anti-elastin peptide antibody was not significantly different from that in the urine of heav smokers (7.42±0.95g/mg creatinine). The ELISA for the detection of elastin peptide in human urine using anti-α-elastin antibody described here may be useful for monitoring of elastin metabolism in patients with a variety of connective tissue abnormalities.