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Báo cáo khoa học: Ribonucleases with angiogenic and bactericidal activities from the Atlantic salmon
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The importance of fish in vertebrate evolution has been better recognized in recent years after the intense work carried out on fish genomics. The recent discovery that fish genomes comprise homologs of ribonucleases, studied before only in tetrapods, and the isolation of ribonucleases from zebrafish have suggested an experimental model for studying fish and verte-brate evolution. | ỊFEBS Journal Ribonucleases with angiogenic and bactericidal activities from the Atlantic salmon Elio Pizzo1 Mario Varcamonti1 Antimo D. Maro2 Anna Zanfardino1 Concetta Giancola3 and Giuseppe D Alessio1 1 Department of Structuraland FunctionalBiology University of Naples Federico II Italy 2 Department of Life Sciences Second University of Naples Caserta Italy 3 Department of Chemistry University of Naples Federico II Italy Keywords angiogenins bactericidal proteins molecular evolution ribonucleases salmon Correspondence G. D Alessio Department of Structuraland FunctionalBiology University of Naples Federico II Via Cintia 80126 Napoli Italy Fax 39 081 679159 Tel 39 081 679157 E-mail dalessio@unina.it Received 13 November 2007 revised 21 December 2007 accepted 14 January 2008 doi 10.1111 j.1742-4658.2008.06289.x The importance of fish in vertebrate evolution has been better recognized in recent years after the intense work carried out on fish genomics. The recent discovery that fish genomes comprise homologs of ribonucleases studied before only in tetrapods and the isolation of ribonucleases from zebrafish have suggested an experimental model for studying fish and vertebrate evolution. Thus the cDNAs encoding the RNases from the Atlantic salmon were expressed and the recombinant RNases Ss-RNase-1 and Ss-RNase-2 were isolated and characterized as both proteins and for their biological activities. Salmon RNases are less active than RNase A in degrading RNA but are both sensitive to the action of the human cytosolic RNase inhibitor. The two enzymes possess both angiogenic and bactericidal activities. However catalytically inactivated Ss-RNases do not exert any angiogenic activity but preserve their full bactericidal activity which is surprisingly preserved even when the enzyme proteins are fully denatured. Analyses of the conformational stability of the two RNases has revealed that they are as stable as typical RNases of the superfamily and Ss-RNase-2 the most active as