{"id":{"repo_id":"toronto-retro","oai_identifier":"oai:utoronto.scholaris.ca:1807/11244"},"canonical_url":"https://search.dev.ndltd.org/etd/toronto-retro/oai:utoronto.scholaris.ca:1807/11244","repository":{"repo_id":"toronto-retro","name":"University of Toronto","base_url":"https://utoronto.scholaris.ca/server/oai/request"},"display":{"title":"Cell Targeted Ribosome Inactivating Proteins Derived from Protein Combinatorial Libraries","abstract":"Combinatorial protein libraries based on a protein template offer a vast potential for deriving protein variants harboring new receptor specificity while retaining other tem-plate functions to serve as library search-engines, cell-routing sequences and therapeutic domains. This concept was tested with the design and synthesis of protein libraries where short random peptide motifs were embedded directly within the catalytic A subunit of the bacterial ribosome-inactivating protein (RIP) known as Shiga-like toxin 1 (SLT-1). More precisely, a seven amino acid peptide epitope (PDTRPAP) was inserted between residues 245-246 of its A subunit (SLT-1APDTRPAP) and shown to preserve catalytic function while exposing the epitope. SLT-1 A chain libraries harboring tripep-tide and heptapeptide random elements were subsequently constructed, screened and shown to express more than 90% of expected cytotoxic A chain variants. Finally, more than 9,000 purified SLT-1 A chain variants were screened using their ribosome-inactivating function in a cell-based assay to identify mutants that are able to kill human melanoma 518-A2 cells. This search led to the striking discovery of a single chain RIP that displays selectivity for a panel of human melanoma cell lines as well as minimal immunogenicity when injected repeatedly into mice. This directed evolution of a RIP template provides a broad platform for identifying cell type specific cytotoxic agents.","abstract_html":"Combinatorial protein libraries based on a protein template offer a vast potential for deriving protein variants harboring new receptor specificity while retaining other tem-plate functions to serve as library search-engines, cell-routing sequences and therapeutic domains. This concept was tested with the design and synthesis of protein libraries where short random peptide motifs were embedded directly within the catalytic A subunit of the bacterial ribosome-inactivating protein (RIP) known as Shiga-like toxin 1 (SLT-1). More precisely, a seven amino acid peptide epitope (PDTRPAP) was inserted between residues 245-246 of its A subunit (SLT-1APDTRPAP) and shown to preserve catalytic function while exposing the epitope. SLT-1 A chain libraries harboring tripep-tide and heptapeptide random elements were subsequently constructed, screened and shown to express more than 90% of expected cytotoxic A chain variants. Finally, more than 9,000 purified SLT-1 A chain variants were screened using their ribosome-inactivating function in a cell-based assay to identify mutants that are able to kill human melanoma 518-A2 cells. This search led to the striking discovery of a single chain RIP that displays selectivity for a panel of human melanoma cell lines as well as minimal immunogenicity when injected repeatedly into mice. This directed evolution of a RIP template provides a broad platform for identifying cell type specific cytotoxic agents.","abstract_has_math":false,"creators":["Perampalam, Subodini"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":"Medical Biophysics","school":null,"contributors":[],"advisors":["Gariepy, Jean"],"committee_chairs":[],"committee_members":[],"year":2008,"date_issued":"2008-08-01T21:04:03Z","date_published":"2008-08-01T21:04:03Z","updated_at":"2026-07-27T21:28:07Z","subjects":["Protein libraries","cytotoxicity","anti-cancer agents","shiga like toxin 1","ribosome inactivating protein"],"languages":["en_ca"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1807/11244","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Gariepy, Jean"]},{"key":"dc:contributor.department","label":"Department","values":["Medical Biophysics"]},{"key":"dc:creator","label":"Author","values":["Perampalam, Subodini"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2008-06"]},{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2008-08-01T21:04:03Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["NO_RESTRICTION","2008-08-01T21:04:03Z"]},{"key":"dc:date.issued","label":"Date","values":["2008-08-01T21:04:03Z"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Protein libraries","cytotoxicity","anti-cancer agents","shiga like toxin 1","ribosome inactivating protein"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en_ca"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/1807/11244"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Combinatorial protein libraries based on a protein template offer a vast potential for deriving protein variants harboring new receptor specificity while retaining other tem-plate functions to serve as library search-engines, cell-routing sequences and therapeutic domains. This concept was tested with the design and synthesis of protein libraries where short random peptide motifs were embedded directly within the catalytic A subunit of the bacterial ribosome-inactivating protein (RIP) known as Shiga-like toxin 1 (SLT-1). More precisely, a seven amino acid peptide epitope (PDTRPAP) was inserted between residues 245-246 of its A subunit (SLT-1APDTRPAP) and shown to preserve catalytic function while exposing the epitope. SLT-1 A chain libraries harboring tripep-tide and heptapeptide random elements were subsequently constructed, screened and shown to express more than 90% of expected cytotoxic A chain variants. Finally, more than 9,000 purified SLT-1 A chain variants were screened using their ribosome-inactivating function in a cell-based assay to identify mutants that are able to kill human melanoma 518-A2 cells. This search led to the striking discovery of a single chain RIP that displays selectivity for a panel of human melanoma cell lines as well as minimal immunogenicity when injected repeatedly into mice. This directed evolution of a RIP template provides a broad platform for identifying cell type specific cytotoxic agents."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["PhD"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Cell Targeted Ribosome Inactivating Proteins Derived from Protein Combinatorial Libraries"]}]}],"canonical_facts":{"dc:contributor.advisor":["Gariepy, Jean"],"dc:contributor.department":["Medical Biophysics"],"dc:creator":["Perampalam, Subodini"],"dc:date":["2008-06"],"dc:date.accessioned":["2008-08-01T21:04:03Z"],"dc:date.available":["NO_RESTRICTION","2008-08-01T21:04:03Z"],"dc:date.issued":["2008-08-01T21:04:03Z"],"dc:description.abstract":["Combinatorial protein libraries based on a protein template offer a vast potential for deriving protein variants harboring new receptor specificity while retaining other tem-plate functions to serve as library search-engines, cell-routing sequences and therapeutic domains. This concept was tested with the design and synthesis of protein libraries where short random peptide motifs were embedded directly within the catalytic A subunit of the bacterial ribosome-inactivating protein (RIP) known as Shiga-like toxin 1 (SLT-1). More precisely, a seven amino acid peptide epitope (PDTRPAP) was inserted between residues 245-246 of its A subunit (SLT-1APDTRPAP) and shown to preserve catalytic function while exposing the epitope. SLT-1 A chain libraries harboring tripep-tide and heptapeptide random elements were subsequently constructed, screened and shown to express more than 90% of expected cytotoxic A chain variants. Finally, more than 9,000 purified SLT-1 A chain variants were screened using their ribosome-inactivating function in a cell-based assay to identify mutants that are able to kill human melanoma 518-A2 cells. This search led to the striking discovery of a single chain RIP that displays selectivity for a panel of human melanoma cell lines as well as minimal immunogenicity when injected repeatedly into mice. This directed evolution of a RIP template provides a broad platform for identifying cell type specific cytotoxic agents."],"dc:description.degree":["PhD"],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/1807/11244"],"dc:language.iso":["en_ca"],"dc:subject":["Protein libraries","cytotoxicity","anti-cancer agents","shiga like toxin 1","ribosome inactivating protein"],"dc:title":["Cell Targeted Ribosome Inactivating Proteins Derived from Protein Combinatorial Libraries"],"dc:type":["Thesis"]},"updated_at":"2026-07-27T21:28:07Z"}