Expression of the non-glycosylated kringle domain of tissue type plasminogen activator in Pichia and its anti-endothelial cell activity

Protein Expr Purif. 2006 Nov;50(1):1-8. doi: 10.1016/j.pep.2006.06.002. Epub 2006 Jun 9.

Abstract

The two-kringle domain of tissue-type plasminogen activator (TK1-2) has been identified as a potent angiogenesis inhibitor by suppressing endothelial cell proliferation, in vivo angiogenesis, and in vivo tumor growth. Escherichia coli-derived, non-glycosylated TK1-2 more potently inhibits in vivo tumor growth, whereas Pichia expression system is more efficient for producing TK1-2 as a soluble form, albeit accompanying N-glycosylation. Therefore, in order to avoid immune reactivity and improve in vivo efficacy, we expressed the non-glycosylated form of TK1-2 in Pichia pastoris and evaluated its activity in vitro. When TK1-2 was mutated at either Asn(117) or Asn(184) by replacing with Gln, the mutated proteins produced the glycosylated form in Pichia, of which sugar moiety could be deleted by endoglycosidase H treatment. When both sites were replaced by Gln, the resulting mutant produced a non-glycosylated protein, NQ-TK1-2. Secreted NQ-TK1-2 was purified from the culture broth by sequential ion exchange chromatography using SP-sepharose, Q-spin, and UNO-S1 column. The purified NQ-TK1-2 migrated as a single protein band of approximately 20 kDa in SDS-PAGE and its mass spectrum showed one major peak of 19,950.71 Da, which is smaller than those of two glycosylated forms of wild type TK1-2. Functionally, the purified NQ-TK1-2 inhibited endothelial cell proliferation and migration stimulated by bFGF and VEGF, respectively. Therefore, the results suggest that non-glycosylated TK1-2 useful for the treatment of cancer can be efficiently produced in Pichia, with retaining its activity.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiogenesis Inhibitors / genetics
  • Angiogenesis Inhibitors / isolation & purification
  • Angiogenesis Inhibitors / pharmacology
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Cells, Cultured
  • Dose-Response Relationship, Drug
  • Endothelial Cells / drug effects*
  • Fibroblast Growth Factor 2 / pharmacology
  • Gene Expression Regulation, Enzymologic*
  • Humans
  • Kringles / genetics*
  • Mutagenesis, Site-Directed
  • Pichia / genetics*
  • Structure-Activity Relationship
  • Thymidine Kinase / genetics
  • Thymidine Kinase / isolation & purification
  • Thymidine Kinase / pharmacology
  • Tissue Plasminogen Activator / genetics*
  • Tissue Plasminogen Activator / isolation & purification
  • Tissue Plasminogen Activator / pharmacology*
  • Vascular Endothelial Growth Factors / pharmacology

Substances

  • Angiogenesis Inhibitors
  • Vascular Endothelial Growth Factors
  • Fibroblast Growth Factor 2
  • thymidine kinase 2
  • Thymidine Kinase
  • thymidine kinase 1
  • Tissue Plasminogen Activator