{"id":{"repo_id":"cape-town","oai_identifier":"oai:open.uct.ac.za:11427/26555"},"canonical_url":"https://search.dev.ndltd.org/etd/cape-town/oai:open.uct.ac.za:11427/26555","repository":{"repo_id":"cape-town","name":"University of Cape Town","base_url":"https://open.uct.ac.za/oai/request"},"display":{"title":"Metals and the conformation of fibrin","abstract":"The carboxy terminal of the γ-chain of human fibrinogen contains at least three biologically. important functional domains: (i) the fibrinogen γ-chain polymerisation centre, (ii) the platelet receptor domain and (iii) the site for staphyloccocal clumping. The nature of the site specificity of these interactions necessitates the existence of a preferred conformation for this region, the nature of which has yet to be clearly established. A novel zinc metalloproteinase isolated from puff adder venom (PAV protease) capable of specifically cleaving the di-γ-chain of transglutaminase (Factor XIIIa) catalysed crosslinked plasmin derived D-dimer into apparently symmetrical monomers has been described. The activity is fibrin specific and displays an unusual site specificity for the γ-carboxy terminal domains within the crosslink region. The activity was reported to be potentiated by zinc. The effect of zinc on the digestion of D-dimer by PAV protease was evaluated by SDS-PAGE and by a fluorimetric technique utilising a fluorescent dansylcadaverine conjugate of the substrate (f-D-dimer). A differential zinc binding study determined that the potentiation of activity by zinc was due to a zinc-substrate rather than a zinc-enzyme interaction. The binding constant for zinc to D-dimer was determined by Scatchard analysis of zinc titration data. The interaction of zinc and f-D-dimer was confirmed by fluorescence anisotropy determinations. The nature of the coordination capsule around the metal cation was determined by examining a cobalt-fibrin-D-dimer complex and characterising the difference visible absorption spectrum thereof. The donor ligands from the D-dimer fragment for the metal ion were determined as histidines by examining zinc(II) and cobalt(II) binding to diethylpyrocarbonate modified fibrin-D-dimer and hydroxylamine treated DEPC-fibrin-D-dimer. Through this study it has been established that the PAV protease cleavage of the di-γ-chain of the plasmin derived D-dimer fragment is potentiated by zinc(II) ions through the formation of a novel zinc determined conformation of fibrin-D-dimer. This presents the possibility of a fibrinspecific neo-epitope being manifested in the presence of zinc ions that could provide a means to determine fibrin degradation products more specifically. A model for the neo-epitope has been proposed.","abstract_html":"The carboxy terminal of the γ-chain of human fibrinogen contains at least three biologically. important functional domains: (i) the fibrinogen γ-chain polymerisation centre, (ii) the platelet receptor domain and (iii) the site for staphyloccocal clumping. The nature of the site specificity of these interactions necessitates the existence of a preferred conformation for this region, the nature of which has yet to be clearly established. A novel zinc metalloproteinase isolated from puff adder venom (PAV protease) capable of specifically cleaving the di-γ-chain of transglutaminase (Factor XIIIa) catalysed crosslinked plasmin derived D-dimer into apparently symmetrical monomers has been described. The activity is fibrin specific and displays an unusual site specificity for the γ-carboxy terminal domains within the crosslink region. The activity was reported to be potentiated by zinc. The effect of zinc on the digestion of D-dimer by PAV protease was evaluated by SDS-PAGE and by a fluorimetric technique utilising a fluorescent dansylcadaverine conjugate of the substrate (f-D-dimer). A differential zinc binding study determined that the potentiation of activity by zinc was due to a zinc-substrate rather than a zinc-enzyme interaction. The binding constant for zinc to D-dimer was determined by Scatchard analysis of zinc titration data. The interaction of zinc and f-D-dimer was confirmed by fluorescence anisotropy determinations. The nature of the coordination capsule around the metal cation was determined by examining a cobalt-fibrin-D-dimer complex and characterising the difference visible absorption spectrum thereof. The donor ligands from the D-dimer fragment for the metal ion were determined as histidines by examining zinc(II) and cobalt(II) binding to diethylpyrocarbonate modified fibrin-D-dimer and hydroxylamine treated DEPC-fibrin-D-dimer. Through this study it has been established that the PAV protease cleavage of the di-γ-chain of the plasmin derived D-dimer fragment is potentiated by zinc(II) ions through the formation of a novel zinc determined conformation of fibrin-D-dimer. This presents the possibility of a fibrinspecific neo-epitope being manifested in the presence of zinc ions that could provide a means to determine fibrin degradation products more specifically. A model for the neo-epitope has been proposed.","abstract_has_math":false,"creators":["Naidoo, Dhesigen P"],"institution":"Division of Chemical Pathology","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Purvis, Langley R"],"committee_chairs":[],"committee_members":[],"year":1992,"date_issued":"1992","date_published":"1992","updated_at":"2026-07-22T22:23:07Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/11427/26555","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Purvis, Langley R"]},{"key":"dc:creator","label":"Author","values":["Naidoo, Dhesigen P"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2017-12-12T10:55:32Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2017-12-12T10:55:32Z"]},{"key":"dc:date.issued","label":"Date","values":["1992"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Division of Chemical Pathology"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cape Town"]},{"key":"dc:type","label":"Dc Type","values":["Master Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Masters"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["MSc (Med)"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/11427/26555"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The carboxy terminal of the γ-chain of human fibrinogen contains at least three biologically. important functional domains: (i) the fibrinogen γ-chain polymerisation centre, (ii) the platelet receptor domain and (iii) the site for staphyloccocal clumping. The nature of the site specificity of these interactions necessitates the existence of a preferred conformation for this region, the nature of which has yet to be clearly established. A novel zinc metalloproteinase isolated from puff adder venom (PAV protease) capable of specifically cleaving the di-γ-chain of transglutaminase (Factor XIIIa) catalysed crosslinked plasmin derived D-dimer into apparently symmetrical monomers has been described. The activity is fibrin specific and displays an unusual site specificity for the γ-carboxy terminal domains within the crosslink region. The activity was reported to be potentiated by zinc. The effect of zinc on the digestion of D-dimer by PAV protease was evaluated by SDS-PAGE and by a fluorimetric technique utilising a fluorescent dansylcadaverine conjugate of the substrate (f-D-dimer). A differential zinc binding study determined that the potentiation of activity by zinc was due to a zinc-substrate rather than a zinc-enzyme interaction. The binding constant for zinc to D-dimer was determined by Scatchard analysis of zinc titration data. The interaction of zinc and f-D-dimer was confirmed by fluorescence anisotropy determinations. The nature of the coordination capsule around the metal cation was determined by examining a cobalt-fibrin-D-dimer complex and characterising the difference visible absorption spectrum thereof. The donor ligands from the D-dimer fragment for the metal ion were determined as histidines by examining zinc(II) and cobalt(II) binding to diethylpyrocarbonate modified fibrin-D-dimer and hydroxylamine treated DEPC-fibrin-D-dimer. Through this study it has been established that the PAV protease cleavage of the di-γ-chain of the plasmin derived D-dimer fragment is potentiated by zinc(II) ions through the formation of a novel zinc determined conformation of fibrin-D-dimer. This presents the possibility of a fibrinspecific neo-epitope being manifested in the presence of zinc ions that could provide a means to determine fibrin degradation products more specifically. A model for the neo-epitope has been proposed."]},{"key":"dc:title","label":"Title","values":["Metals and the conformation of fibrin"]}]}],"canonical_facts":{"dc:contributor.advisor":["Purvis, Langley R"],"dc:creator":["Naidoo, Dhesigen P"],"dc:date.accessioned":["2017-12-12T10:55:32Z"],"dc:date.available":["2017-12-12T10:55:32Z"],"dc:date.issued":["1992"],"dc:description.abstract":["The carboxy terminal of the γ-chain of human fibrinogen contains at least three biologically. important functional domains: (i) the fibrinogen γ-chain polymerisation centre, (ii) the platelet receptor domain and (iii) the site for staphyloccocal clumping. The nature of the site specificity of these interactions necessitates the existence of a preferred conformation for this region, the nature of which has yet to be clearly established. A novel zinc metalloproteinase isolated from puff adder venom (PAV protease) capable of specifically cleaving the di-γ-chain of transglutaminase (Factor XIIIa) catalysed crosslinked plasmin derived D-dimer into apparently symmetrical monomers has been described. The activity is fibrin specific and displays an unusual site specificity for the γ-carboxy terminal domains within the crosslink region. The activity was reported to be potentiated by zinc. The effect of zinc on the digestion of D-dimer by PAV protease was evaluated by SDS-PAGE and by a fluorimetric technique utilising a fluorescent dansylcadaverine conjugate of the substrate (f-D-dimer). A differential zinc binding study determined that the potentiation of activity by zinc was due to a zinc-substrate rather than a zinc-enzyme interaction. The binding constant for zinc to D-dimer was determined by Scatchard analysis of zinc titration data. The interaction of zinc and f-D-dimer was confirmed by fluorescence anisotropy determinations. The nature of the coordination capsule around the metal cation was determined by examining a cobalt-fibrin-D-dimer complex and characterising the difference visible absorption spectrum thereof. The donor ligands from the D-dimer fragment for the metal ion were determined as histidines by examining zinc(II) and cobalt(II) binding to diethylpyrocarbonate modified fibrin-D-dimer and hydroxylamine treated DEPC-fibrin-D-dimer. Through this study it has been established that the PAV protease cleavage of the di-γ-chain of the plasmin derived D-dimer fragment is potentiated by zinc(II) ions through the formation of a novel zinc determined conformation of fibrin-D-dimer. This presents the possibility of a fibrinspecific neo-epitope being manifested in the presence of zinc ions that could provide a means to determine fibrin degradation products more specifically. A model for the neo-epitope has been proposed."],"dc:identifier.uri":["http://hdl.handle.net/11427/26555"],"dc:language.iso":["eng"],"dc:publisher.department":["Division of Chemical Pathology"],"dc:publisher.institution":["University of Cape Town"],"dc:title":["Metals and the conformation of fibrin"],"dc:type":["Master Thesis"],"dc:type.qualificationlevel":["Masters"],"dc:type.qualificationname":["MSc (Med)"]},"updated_at":"2026-07-22T22:23:07Z"}