Ribonuclease A can be transformed into a dimeric ribonuclease with antitumor activity.
A cDNA coding for bovine pancreatic RNase A was mutagenized to insert a proline, a leucine, and 2 cysteine residues, i.e. the residues present at corresponding positions in the subunit of seminal RNase, the only dimeric RNase of the pancreatic-type superfamily. The mutant, expressed in Escherichia coli, eventually aggregated into catalytically active dimers. Like naturally dimeric seminal RNase, at equilibrium the mutant dimeric RNase A adopted two quaternary structures (one with an exchange of the N-terminal segments between partner subunits, the other with no exchange) and displayed a selective toxicity for malignant cells, absent in the monomeric, parent protein.
Dipartimento di Chimica Organica e Biologica, Università Federico II di Napoli, Italy.
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Di Donato
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Cafaro
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D'Alessio
D016475:3T3 Cells; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D002417:Cattle; D002461:Cell Line, Transformed; D002850:Chromatography, Gel; D018076:DNA, Complementary; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli; D051379:Mice; D008807:Mice, Inbred BALB C; D016254:Mutagenesis, Insertional; D010179:Pancreas / Q000201:enzymology; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D012259:Ribonuclease, Pancreatic / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*
D000970:Antineoplastic Agents; D018076:DNA, Complementary; D011994:Recombinant Proteins; D012259:Ribonuclease, Pancreatic