Increased binding of limulin to alpha 2-macroglobulin and immunoglobulin M from cystic fibrosis patients.

In the present study the binding of limulin, a lectin with sialic acid specificity, to three serum glycoproteins from controls and cystic fibrosis patients was compared. alpha 2-Macroglobulin from patients with cystic fibrosis was shown to have significantly increased binding to the lectin limulin when compared to that from healthy controls (t = 3.6, p less than 0.01). The binding of limulin to immunoglobulin M (IgM) from cystic fibrosis patients was also shown to be significantly higher than the binding to IgM from controls (t = 3.6, p less than 0.01), whereas no detectable binding of fluorescein-conjugated limulin to immunoglobulin G from either cystic fibrosis patients or controls was observed. These findings support the hypothesis that the underlying inherited defect in cystic fibrosis might be an abnormal synthesis or degradation of glycoproteins and glycopeptides.