title: The rabbit properdin system: I. Identification of a new factor and purification of rabbit properdin.
abstract: Pure preparations of rabbit properdin were obtained from rabbit serum by ion-exchange chromatography. These preparations functioned as properdin when they were measured with the zymosan assay or with a serum reagent selectively depleted of properdin by a specific immunoabsorbent. Properdin in these preparations was in its activated state. A new serum factor was required to measure properdin activity when purified preparations of rabbit properdin were tested with the zymosan assay. This factor was designated as ZBP, or zymosan-binding protein. ZBP appeared to be distinct from known components of the alternative complement pathway and the classical complement system, and it did not appear to be an immunoglobulin.
mesh_terms: D000818:Animals; D001798:Blood Proteins; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003176:Complement C3; D011415:Complement Factor B; D003170:Complement Pathway, Alternative; D006801:Humans; D009994:Osmolar Concentration; D011414:Properdin / Q000302:isolation & purification*; D011485:Protein Binding; D011817:Rabbits / Q000097:blood*; D015054:Zymosan / Q000494:pharmacology
chemical_list: D001798:Blood Proteins; D003176:Complement C3; D011414:Properdin; D015054:Zymosan; D011415:Complement Factor B