A biologically active angiogenesis inhibitor, human serum albumin-TIMP-2 fusion protein, secreted from Saccharomyces cerevisiae.

Tissue inhibitor of metalloproteinase-2 (TIMP-2) is an endogenous and bi-functional inhibitor of angiogenesis. TIMP-2 is expressed in an insoluble form in Escherichia coli and secreted at a very low level from yeast. Here, we report on a high level of secretion of TIMP-2 fused with human serum albumin (HSA) from the yeast Saccharomyces cerevisiae. The secreted HSA-TIMP-2 fusion protein (87kDa) was purified to greater than 95% homogeneity. The HSA-TIMP-2 protein inhibited approximately 81% of tube formation of human umbilical vein endothelial cells (HUVECs) when studied at a concentration of 187microM. The systemic administration of HSA-TIMP-2 at 40mg/kg to the C57B1/6 mouse inhibited the growth of B16BL6 tumors. Furthermore, a combination treatment of HSA-TIMP-2 with 5-fluorouracil (50mg/kg) showed significant effects on tumor growth in this model. The high level of secretion of the biologically active angiogenesis inhibitor from S. cerevisiae should facilitate fundamental research and application studies of HSA-TIMP-2, as an attractive candidate for therapeutic agents treating angiogenesis-related diseases.