X-ray crystallographic examination of a bovine antibody (BLV1H12) unveiled a distinctive scaffold in its ultralong hefty chain complementarity determining area 3 (CDR3H) that folds into a solvent exposed, antiparallel beta-stranded "stalk" fused selleck products with a disulfide cross-linked "knob" domain. This uncommon variable region motif presents a novel method for making chimeric antibodies with novel routines. Towards this finish, human erythropoietin (hEPO) was substituted for the "knob" domain within this antibody to afford an antibody-hEPO (Ab-hEPO) fusion protein that effectively expresses in mammalian cellsCSF-1R . Ab-hEPO proliferated TF-1 cells by using a potency comparable to that of hEPO (EC50 just like 0.03 nM) and exhibits a considerably extended plasma half-life (>6 days) in mice relative to hEPO (similar to 4 h). Mice treated with the Ab-hEPO fusion protein show sustained elevated hematocrit for more than two weeks. This work demonstrates the utility of BLV1H12 CDR3 fusions as aselleck chemicals Doxorubicin novel strategy for creating potent polypeptides with enhanced pharmacological properties.