Mutant proteins of human DNA topoisomerase I

摘要

PCT No. PCT/JP94/02280 Sec. 371 Date Nov. 26, 1996 Sec. 102(e) Date Nov. 26, 1996 PCT Filed Dec. 28, 1994 PCT Pub. No. WO95/18218 PCT Pub. Date Jul. 6, 1995Mutant proteins of human DNA topoisomerase I having an amino acid sequence in which tyrosine at the 592nd position of human DNA topoisomerase I is lacking or replaced with phenylalanine and which contains at least 30 amino acids in succession of the amino acid sequence subsequent to the 542nd amino acid of human DNA topoisomerase I. Above described mutant proteins react with anti-Scl-70, antibody in the sera of autoimmune disease patients of diffuse scleroderma and can be produced by genetic engineering using E. coli, and therefore they are useful as a diagnostic agent of scleroderma.