title: Protein-protein interface-binding peptides inhibit the cancer therapy target human thymidylate synthase.
abstract: Human thymidylate synthase is a homodimeric enzyme that plays a key role in DNA synthesis and is a target for several clinically important anticancer drugs that bind to its active site. We have designed peptides to specifically target its dimer interface. Here we show through X-ray diffraction, spectroscopic, kinetic, and calorimetric evidence that the peptides do indeed bind at the interface of the dimeric protein and stabilize its di-inactive form. The "LR" peptide binds at a previously unknown binding site and shows a previously undescribed mechanism for the allosteric inhibition of a homodimeric enzyme. It inhibits the intracellular enzyme in ovarian cancer cells and reduces cellular growth at low micromolar concentrations in both cisplatin-sensitive and -resistant cells without causing protein overexpression. This peptide demonstrates the potential of allosteric inhibition of hTS for overcoming platinum drug resistance in ovarian cancer.
authors.affiliation: Department of Pharmaceutical Sciences, via Campi 183, University of Modena and Reggio Emilia, 41126 Modena, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Cardinale
authors.forename: Giambattista
authors.initials: G
authors.lastname: Guaitoli
authors.forename: Donatella
authors.initials: D
authors.lastname: Tondi
authors.forename: Rosaria
authors.initials: R
authors.lastname: Luciani
authors.forename: Stefan
authors.initials: S
authors.lastname: Henrich
authors.forename: Outi M H
authors.initials: OM
authors.lastname: Salo-Ahen
authors.forename: Stefania
authors.initials: S
authors.lastname: Ferrari
authors.forename: Gaetano
authors.initials: G
authors.lastname: Marverti
authors.forename: Davide
authors.initials: D
authors.lastname: Guerrieri
authors.forename: Alessio
authors.initials: A
authors.lastname: Ligabue
authors.forename: Chiara
authors.initials: C
authors.lastname: Frassineti
authors.forename: Cecilia
authors.initials: C
authors.lastname: Pozzi
authors.forename: Stefano
authors.initials: S
authors.lastname: Mangani
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Fessas
authors.forename: Remo
authors.initials: R
authors.lastname: Guerrini
authors.forename: Glauco
authors.initials: G
authors.lastname: Ponterini
authors.forename: Rebecca C
authors.initials: RC
authors.lastname: Wade
authors.forename: M Paola
authors.initials: MP
authors.lastname: Costi
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology / Q000627:therapeutic use; D018360:Crystallography, X-Ray; D015195:Drug Design; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D005472:Fluorouracil / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D058990:Molecular Targeted Therapy; D010051:Ovarian Neoplasms / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology; D010455:Peptides / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology* / Q000627:therapeutic use; D011485:Protein Binding / Q000187:drug effects; D011487:Protein Conformation; D055503:Protein Multimerization / Q000187:drug effects; D013816:Thermodynamics; D013940:Thymidylate Synthase / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D010455:Peptides; D013940:Thymidylate Synthase; D002945:Cisplatin; D005472:Fluorouracil