Toward an Antitumor Form of Bovine Pancreatic Ribonuclease: The Crystal Structure of Three Noncovalent Dimeric Mutants(528 views) Merlino A, Russo Krauss I, Perillo M, Mattia CA, Ercole C, Picone D, Vergara A, Sica F
Keywords: 3d-Domain Swapping, Antitumor Activity, Bovine Seminal Ribonuclease, Crystal Structure, Helix Exchange, Noncovalent Dimer, Protein Mutations And Evolution, Quaternary Structure Flexibility, Swapped Dimers, Anti-Tumor Activities, Amines, Amino Acids, Enzymes, Peptides, Three Dimensional, Cysteine, Glycine, Leucine, Pancreatic Ribonuclease, Proline, Deoxyguanosine, Ribonuclease Inhibitor, Solvent, Amino Acid Sequence, Amino Terminal Sequence, Antineoplastic Activity, Article, Complex Formation, Controlled Study, Drug Structure, Enzyme Engineering, Hinge Region, Protein Quaternary Structure, Amino Acid Composition, Cytotoxicity, Dimerization, Enzyme Substrate, Gel Permeation Chromatography, Protein Binding, Protein Engineering, Animals, Antineoplastic Agents, Catalytic Domain, Cattle, Crystallography, X-Ray, Endoribonucleases, Isoenzymes, Models, Molecular, Protein Multimerization, Protein Structure, Tertiary, Recombinant Proteins, Structure-Activity Relationship,
Affiliations: *** IBB - CNR ***
Department of Chemistry, University of Naples Federico II Complesso Universitario Monte S. Angelo, Via Cinthia, I-80126 Naples, Italy
Istituto di Biostrutture e Bioimmagini, CNR, Via Mezzocannone 16, I-80134 Naples, Italy
Department of Pharmaceutical Science, University of Salerno, via Ponte don Melillo, I-84084 Fisciano (SA), Italy
References: Not available.
Toward an Antitumor Form of Bovine Pancreatic Ribonuclease: The Crystal Structure of Three Noncovalent Dimeric Mutants
The cytotoxic action of bovine seminal ribonuclease (BS-RNase) depends on its noncovalent swapped dimeric form (NCD-BS), which presents a compact structure that allows the molecule to escape ribonuclease inhibitor (RI). A Key role in the acquisition of this structure has been attributed to the concomitant presense of a proline in position 19 and a leucine in position 28. This introduction of Leu28, Cys31, and Cys32 and, in addition, of Pro19 in the sequence of bovine pancreatic ribonuclease (RNase A) has produced two dimeric variants LCC and PLCC, which do exhibit a cytotoxic activity, though at a much lower level than BS-RNase. The crystal structure analysis of the noncovalent swapped form (NCD) of LCC and PLCG complexed with the substrate analogue 2'-deoxycytidylyl(3',5')-2'-deoxyguanosine, has revealed that, differently from NCD-BS, the dimers adopt an opened quaternary structure, with the two Leu residues fully exposed to the solvent, that does not hinder the binding of RI. similar results have been obtained for a third mutant of the pancreatic enzyme, engineered with the hinge peptide sequence of the seminal enzyme (residues 16-22) and the two cysteines in position 31 and 31, but lacking the hydrophobic Leu residue in position. 28. The comparison of these three structures with those previously reported for other ribonuclease swapped dimers strongly suggests that, in addition to Pro19 and Leu28, the presence of a glycine at the N-terminal end of the hinge peptide is also important to push the swapped form of RNase A dimer into the compact quaternary organization observed for NCD-BS. (c) 2009 Wiley Periodicals, Inc. Biopolymers 91: 1029-1037, 2009.
Toward an Antitumor Form of Bovine Pancreatic Ribonuclease: The Crystal Structure of Three Noncovalent Dimeric Mutants