Objective    To confirm the interaction between periostin (osteoblast-specific factor 2) and secreted frizzled-related protein 2 (SFRP2) by co-immunoprecipitation and HPLC-Chip/MS techniques.   Methods   Expression vector encoding HA-tagged fusion protein HA-Periostin was constructed

identified and transfected into human embryo kidney 293 (HEK293) cells alone or with the expression vector pMCV-Myc-SFRP2 containing Myc-tagged fusion protein Myc-SFRP2. The interaction between SFRP2 and periostin was detected by co-immunoprecipitation with the aid of anti-Myc antibody first. Then SDS-PAGE was perform

and the blots of the protein complexes were analyzed by HPLC-Chip/MS techniques. Spectrum Mill was employed to identify the protein complexes by searching Swissport database.   Results   From the Myc-SFRP2 immunoprecipitation complex

periostin was identified by protein sequencing.   Conclusion   There is an interaction between SFRP2 and periostin.