Insertional-fusion of basic fibroblast growth factor endowed ribonuclease 1 with enhanced cytotoxicity by steric blockade of inhibitor interaction

Hiroko Tada, Masayuki Onizuka, Kazuko Muraki, Wataru Masuzawa, Junichiro Futami, Megumi Kosaka, Masaharu Seno, Hidenori Yamada

Research output: Contribution to journalArticle

9 Citations (Scopus)


Basic fibroblast growth factor (bFGF) was inserted in the middle of human ribonuclease 1 (RNase1) sequence at an RNase inhibitor (RI)-binding site (Gly89) by a new gene fusion technique, insertional-fusion. The resultant insertional-fusion protein (CL-RFN89) was active both as bFGF and as RNase. Furthermore, it acquired an additional ability of evading RI through steric blockade of RI-binding caused by fused bFGF domain. As a result, CL-RFN89 showed stronger growth inhibition on B16/BL6 melanoma cells than an RI-sensitive tandem fusion protein. Thus, the insertional-fusion technique increases accessible positions for gene fusion on RNase, resulting in construction of a potent cytotoxic RNase.

Original languageEnglish
Pages (from-to)39-43
Number of pages5
JournalFEBS Letters
Issue number1-3
Publication statusPublished - Jun 18 2004



  • Basic fibroblast growth factor
  • bFGF, basic fibroblast growth factor
  • CL-RNase1, 4-118 cross-linked RNase1 mutant
  • Insertional-fusion protein
  • Protein engineering
  • RFNs, insertional-fusion proteins between hRNase1 and bFGF
  • Ribonuclease
  • Targeting

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

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