{"id":{"repo_id":"queens","oai_identifier":"oai:queensu.scholaris.ca:1974/14344"},"canonical_url":"https://search.dev.ndltd.org/etd/queens/oai:queensu.scholaris.ca:1974/14344","repository":{"repo_id":"queens","name":"Queens University","base_url":"https://qspace.library.queensu.ca/server/oai/request"},"display":{"title":"Solid-State 17O NMR as a New Probe to Study Acyl-Enzyme Intermediates","abstract":"This thesis reports on a combined solid-state 17O NMR and quantum mechanical study of three acyl-enzyme intermediates: p-N,N-dimethylaminobenzoyl-chymotrypsin (DAB-CHT), trans¬¬-¬o-methoxycinnamoyl-chymotrypsin (oMC-CHT), and trans-p-methoxycinnamoyl-chymotrypsin (pMC-CHT). At pH 7.8, the three acyl-enzyme intermediates were found to undergo hydrolysis (deacylation) with the following rate constants: DAB-CHT, 6.4 ± 0.1 × 10-6; oMC-CHT, 2.8 ± 0.1 × 10-4 s-1; pMC-CHT, 8.5 ± 0.3 × 10-3 s-1. Analysis of solid-state 17O NMR spectra obtained under the magic angle spinning (MAS) condition at 21 T for the three acyl-enzyme intermediates yields the following isotropic chemical shift (δiso), quadrupolar coupling constant (CQ), and asymmetry parameter (ηQ): DAB-CHT, δiso = 316 ± 2 ppm, CQ = 10.0 ± 1 MHz, ηQ = 0.6 ± 0.2; oMC-CHT, δiso = 316 ± 2 ppm, CQ = 9.2 ± 1 MHz, ηQ = 0.6 ± 0.2; and pMC-CHT, δiso = 316 ± 2, CQ = 7.0 ± 0.5 MHz, ηQ = 0.8 ± 0.2. With the aid of quantum mechanical calculations, these 17O NMR parameters were interpreted as to reflect the variations in hydrogen bonding interactions between the carbonyl (C=O) functional group of the acyl moiety and the two NH groups from the protein backbone in the so-called oxyanion hole. This work represents the first use of solid-state 17O NMR spectroscopy to study acyl-enzyme intermediates and demonstrates the great potential of this new technique.","abstract_html":"This thesis reports on a combined solid-state 17O NMR and quantum mechanical study of three acyl-enzyme intermediates: p-N,N-dimethylaminobenzoyl-chymotrypsin (DAB-CHT), trans¬¬-¬o-methoxycinnamoyl-chymotrypsin (oMC-CHT), and trans-p-methoxycinnamoyl-chymotrypsin (pMC-CHT). At pH 7.8, the three acyl-enzyme intermediates were found to undergo hydrolysis (deacylation) with the following rate constants: DAB-CHT, 6.4 ± 0.1 × 10-6; oMC-CHT, 2.8 ± 0.1 × 10-4 s-1; pMC-CHT, 8.5 ± 0.3 × 10-3 s-1. Analysis of solid-state 17O NMR spectra obtained under the magic angle spinning (MAS) condition at 21 T for the three acyl-enzyme intermediates yields the following isotropic chemical shift (δiso), quadrupolar coupling constant (CQ), and asymmetry parameter (ηQ): DAB-CHT, δiso = 316 ± 2 ppm, CQ = 10.0 ± 1 MHz, ηQ = 0.6 ± 0.2; oMC-CHT, δiso = 316 ± 2 ppm, CQ = 9.2 ± 1 MHz, ηQ = 0.6 ± 0.2; and pMC-CHT, δiso = 316 ± 2, CQ = 7.0 ± 0.5 MHz, ηQ = 0.8 ± 0.2. With the aid of quantum mechanical calculations, these 17O NMR parameters were interpreted as to reflect the variations in hydrogen bonding interactions between the carbonyl (C=O) functional group of the acyl moiety and the two NH groups from the protein backbone in the so-called oxyanion hole. This work represents the first use of solid-state 17O NMR spectroscopy to study acyl-enzyme intermediates and demonstrates the great potential of this new technique.","abstract_has_math":false,"creators":["Tang, Aaron W."],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":"Chemistry","school":null,"contributors":[],"advisors":["Wu, Gang"],"committee_chairs":[],"committee_members":[],"year":2016,"date_issued":"2016-04-30","date_published":"2016-04-30","updated_at":"2026-07-27T20:35:21Z","subjects":["solid-state","Chymotrypsin","acyl-enzyme","magic-angle spinning","NMR","computation","17O"],"languages":["eng"],"rights":["Creative Commons - Attribution - CC BY"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1974/14344","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.department","label":"Department","values":["Chemistry"]},{"key":"dc:contributor.supervisor","label":"Supervisor","values":["Wu, Gang"]},{"key":"dc:creator","label":"Author","values":["Tang, Aaron W."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2016-04-29 19:42:38.179"]},{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2016-04-30T15:52:32Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2016-04-30T15:52:32Z"]},{"key":"dc:date.issued","label":"Date","values":["2016-04-30"]},{"key":"dc:type","label":"Dc Type","values":["thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["solid-state","Chymotrypsin","acyl-enzyme","magic-angle spinning","NMR","computation","17O"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Creative Commons - Attribution - CC BY"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/1974/14344"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Thesis (Master, Chemistry) -- Queen's University, 2016-04-29 19:42:38.179"]},{"key":"dc:description.abstract","label":"Abstract","values":["This thesis reports on a combined solid-state 17O NMR and quantum mechanical study of three acyl-enzyme intermediates: p-N,N-dimethylaminobenzoyl-chymotrypsin (DAB-CHT), trans¬¬-¬o-methoxycinnamoyl-chymotrypsin (oMC-CHT), and trans-p-methoxycinnamoyl-chymotrypsin (pMC-CHT). At pH 7.8, the three acyl-enzyme intermediates were found to undergo hydrolysis (deacylation) with the following rate constants: DAB-CHT, 6.4 ± 0.1 × 10-6; oMC-CHT, 2.8 ± 0.1 × 10-4 s-1; pMC-CHT, 8.5 ± 0.3 × 10-3 s-1. Analysis of solid-state 17O NMR spectra obtained under the magic angle spinning (MAS) condition at 21 T for the three acyl-enzyme intermediates yields the following isotropic chemical shift (δiso), quadrupolar coupling constant (CQ), and asymmetry parameter (ηQ): DAB-CHT, δiso = 316 ± 2 ppm, CQ = 10.0 ± 1 MHz, ηQ = 0.6 ± 0.2; oMC-CHT, δiso = 316 ± 2 ppm, CQ = 9.2 ± 1 MHz, ηQ = 0.6 ± 0.2; and pMC-CHT, δiso = 316 ± 2, CQ = 7.0 ± 0.5 MHz, ηQ = 0.8 ± 0.2. With the aid of quantum mechanical calculations, these 17O NMR parameters were interpreted as to reflect the variations in hydrogen bonding interactions between the carbonyl (C=O) functional group of the acyl moiety and the two NH groups from the protein backbone in the so-called oxyanion hole. This work represents the first use of solid-state 17O NMR spectroscopy to study acyl-enzyme intermediates and demonstrates the great potential of this new technique."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["M.Sc."]},{"key":"dc:title","label":"Title","values":["Solid-State 17O NMR as a New Probe to Study Acyl-Enzyme Intermediates"]}]}],"canonical_facts":{"dc:contributor.department":["Chemistry"],"dc:contributor.supervisor":["Wu, Gang"],"dc:creator":["Tang, Aaron W."],"dc:date":["2016-04-29 19:42:38.179"],"dc:date.accessioned":["2016-04-30T15:52:32Z"],"dc:date.available":["2016-04-30T15:52:32Z"],"dc:date.issued":["2016-04-30"],"dc:description":["Thesis (Master, Chemistry) -- Queen's University, 2016-04-29 19:42:38.179"],"dc:description.abstract":["This thesis reports on a combined solid-state 17O NMR and quantum mechanical study of three acyl-enzyme intermediates: p-N,N-dimethylaminobenzoyl-chymotrypsin (DAB-CHT), trans¬¬-¬o-methoxycinnamoyl-chymotrypsin (oMC-CHT), and trans-p-methoxycinnamoyl-chymotrypsin (pMC-CHT). At pH 7.8, the three acyl-enzyme intermediates were found to undergo hydrolysis (deacylation) with the following rate constants: DAB-CHT, 6.4 ± 0.1 × 10-6; oMC-CHT, 2.8 ± 0.1 × 10-4 s-1; pMC-CHT, 8.5 ± 0.3 × 10-3 s-1. Analysis of solid-state 17O NMR spectra obtained under the magic angle spinning (MAS) condition at 21 T for the three acyl-enzyme intermediates yields the following isotropic chemical shift (δiso), quadrupolar coupling constant (CQ), and asymmetry parameter (ηQ): DAB-CHT, δiso = 316 ± 2 ppm, CQ = 10.0 ± 1 MHz, ηQ = 0.6 ± 0.2; oMC-CHT, δiso = 316 ± 2 ppm, CQ = 9.2 ± 1 MHz, ηQ = 0.6 ± 0.2; and pMC-CHT, δiso = 316 ± 2, CQ = 7.0 ± 0.5 MHz, ηQ = 0.8 ± 0.2. With the aid of quantum mechanical calculations, these 17O NMR parameters were interpreted as to reflect the variations in hydrogen bonding interactions between the carbonyl (C=O) functional group of the acyl moiety and the two NH groups from the protein backbone in the so-called oxyanion hole. This work represents the first use of solid-state 17O NMR spectroscopy to study acyl-enzyme intermediates and demonstrates the great potential of this new technique."],"dc:description.degree":["M.Sc."],"dc:identifier.uri":["http://hdl.handle.net/1974/14344"],"dc:language.iso":["eng"],"dc:rights":["Creative Commons - Attribution - CC BY"],"dc:subject":["solid-state","Chymotrypsin","acyl-enzyme","magic-angle spinning","NMR","computation","17O"],"dc:title":["Solid-State 17O NMR as a New Probe to Study Acyl-Enzyme Intermediates"],"dc:type":["thesis"]},"updated_at":"2026-07-27T20:35:21Z"}