title: Purification and partial sequence of human osteoclast-activating factor: identity with interleukin 1 beta.
abstract: The lymphokine osteoclast-activating factor (OAF) was purified to homogeneity. OAF was produced by human peripheral blood mononuclear cells stimulated with concanavalin A and phorbol myristate acetate under serum-free culture conditions. OAF was purified by sequential gel filtration, ion-exchange, and reverse-phase HPLC by following bone resorptive activity. Homogeneity was indicated by the criteria of a single 17,800-dalton band on silver-stained polyacrylamide gels, a single pI 6.8 band on isoelectric focusing, and a single aminoterminal sequence. Purified OAF stimulated half-maximal release of calcium from fetal rat long bones at a concentration of approximately 0.66 ng/ml. The amino-terminal sequence of OAF was determined and found to be identical to that of interleukin 1 beta. Homogeneous OAF possessed an activity of 8.2 X 10(6) U/mg in the thymocyte proliferation assay. Because the m.w., isoelectric point, amino-terminal sequence, and specific activity in the thymocyte proliferation assay are the same for homogeneous OAF and interleukin 1 beta, we conclude that they are the same molecule, and that interleukin 1 beta is the major protein with OAF activity produced by lectin-stimulated peripheral blood mononuclear cells.
mesh_terms: D000595:Amino Acid Sequence; D001862:Bone Resorption; D002474:Cell-Free System; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D006801:Humans; D007375:Interleukin-1 / Q000032:analysis; D007525:Isoelectric Focusing; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000378:metabolism; D008222:Lymphokines / Q000032:analysis / Q000302:isolation & purification* / Q000502:physiology
chemical_list: D007375:Interleukin-1; D008222:Lymphokines; C008718:osteoclast activating factor