The interaction of a protein from the coelomic fluid of earthworms with staphylococcal protein A.

A Staphylococcal protein A (SpA)-binding protein was isolated from coelomic fluids of the annelids, Lumbricus terrestris (LT) and Eisenia foetida (EF), by affinity chromatography on SpA-Sepharose. Analyses by polyacrylamide gel electrophoresis in sodium dodecyl sulfate (SDS-PAGE) under reducing and nonreducing conditions showed that SpA-binding activity is associated with a single chain protein, with a mol wt of 62 kD. The carbohydrate moiety of this protein consists of 21.4 g/100 g of O-linked and N-linked oligosaccharides. The amino acid composition of SpA-binding protein did not show structural homology with that of human IgG1 heavy chain (Daw), which also binds SpA.