Novel specific chemtactic receptor for S100L protein on guinea pig eosinophils.

We isolated a new chemotactic protein from bovine lung, and its partial protein sequence analysis indicated that this protein was identical with S100L, one member of the Ca2+-binding S100 protein family. The chemotactic activity of S100L on guinea pig eosinophils is observed at 0.1nM protein concentration, and the effects appear mediated by a novel specific surface receptor. We characterized the receptor for S100L on guinea pig eosinophils. Scatchard analyses of the data that [125I]S100L bound to S100L receptor indicate the presence of two receptor populations on eosinophils with a Kd value of 3.3 x 10(-11)M and 1.1 x 10(-9)M. Thus, S100L protein has the most potent chemotactic activity on guinea pig eosinophils of all the chemotactic proteins.