{"id":{"repo_id":"nus","oai_identifier":"oai:scholarbank.nus.edu.sg:10635/22764"},"canonical_url":"https://search.dev.ndltd.org/etd/nus/oai:scholarbank.nus.edu.sg:10635/22764","repository":{"repo_id":"nus","name":"National University of Singapore","base_url":"https://scholarbank.nus.edu.sg/oai/request"},"display":{"title":"Structural Determinants in the folding of epidermal growth factor (EGF)-Like domains","abstract":"The epidermal growth factor (EGF)-like domain is an evolutionarily conserved modular protein subunit. Despite hypervariability of amino acid sequences in their inter-cysteine region, they preferentially fold into a three-looped conformation with a disulfide pairing of C₁-C₃, C₂-C₄, C₅-C₆. To elucidate the structural determinants that dictates the canonical EGF-like domain fold, we had chosen the fourth and fifth EGF-like domain of thrombomodulin (TM) as models. While the fourth EGF-like domain folds into the canonical conformation, the fifth EGF-like domain does not and possesses an alternate disulfide pairing of C₁-C₂, C₃-C₄, C₅-C₆. We examined the folding tendencies of two synthetic peptides corresponding to truncated versions of TM EGF-like domain four and five under air oxidation and redox folding conditions. By identifying the structural isoforms obtained in the folding reaction using regiospecifically-synthesized conformers as controls, we determined that the last segment of both domains (encompassing C₅ and C₆) do not influence the tendencies to fold into their respective native conformations. When folded under denaturing conditions, the folding tendency of the fourth EGF-like domain changes to that of the C₁-C₂, C₃-C₄ conformer. Conversely, the addition of denaturant did not affect the folding tendency of the fifth EGF-like domain. This suggests that side chain interactions are crucial for achieving the canonical EGF-like domain fold but not for the non-canonical fold. Folding under high salt content did not disrupt the folding tendencies of both domains and result in slight increase of the C₁-C₃, C₂-C₄ conformer in both cases. This suggests that hydrophobic interaction, but not electrostatic interaction, is the key in the achieving the canonical fold of EGF-like domains.","abstract_html":"The epidermal growth factor (EGF)-like domain is an evolutionarily conserved modular protein subunit. Despite hypervariability of amino acid sequences in their inter-cysteine region, they preferentially fold into a three-looped conformation with a disulfide pairing of C₁-C₃, C₂-C₄, C₅-C₆. To elucidate the structural determinants that dictates the canonical EGF-like domain fold, we had chosen the fourth and fifth EGF-like domain of thrombomodulin (TM) as models. While the fourth EGF-like domain folds into the canonical conformation, the fifth EGF-like domain does not and possesses an alternate disulfide pairing of C₁-C₂, C₃-C₄, C₅-C₆. We examined the folding tendencies of two synthetic peptides corresponding to truncated versions of TM EGF-like domain four and five under air oxidation and redox folding conditions. By identifying the structural isoforms obtained in the folding reaction using regiospecifically-synthesized conformers as controls, we determined that the last segment of both domains (encompassing C₅ and C₆) do not influence the tendencies to fold into their respective native conformations. When folded under denaturing conditions, the folding tendency of the fourth EGF-like domain changes to that of the C₁-C₂, C₃-C₄ conformer. Conversely, the addition of denaturant did not affect the folding tendency of the fifth EGF-like domain. This suggests that side chain interactions are crucial for achieving the canonical EGF-like domain fold but not for the non-canonical fold. Folding under high salt content did not disrupt the folding tendencies of both domains and result in slight increase of the C₁-C₃, C₂-C₄ conformer in both cases. This suggests that hydrophobic interaction, but not electrostatic interaction, is the key in the achieving the canonical fold of EGF-like domains.","abstract_has_math":false,"creators":["NG AH SOCK ANGIE"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-01-11","date_published":"2011-01-11","updated_at":"2026-07-24T03:32:43Z","subjects":["protein folding code, structural determinants, epidermal growth factor-like domains"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["NG AH SOCK ANGIE"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.issued","label":"Date","values":["2011-01-11"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://scholarbank.nus.edu.sg/handle/10635/22764"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["protein folding code, structural determinants, epidermal growth factor-like domains"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://scholarbank.nus.edu.sg/bitstreams/31d31831-ad52-4102-9e0c-8b5061018051/download"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The epidermal growth factor (EGF)-like domain is an evolutionarily conserved modular protein subunit. Despite hypervariability of amino acid sequences in their inter-cysteine region, they preferentially fold into a three-looped conformation with a disulfide pairing of C₁-C₃, C₂-C₄, C₅-C₆. To elucidate the structural determinants that dictates the canonical EGF-like domain fold, we had chosen the fourth and fifth EGF-like domain of thrombomodulin (TM) as models. While the fourth EGF-like domain folds into the canonical conformation, the fifth EGF-like domain does not and possesses an alternate disulfide pairing of C₁-C₂, C₃-C₄, C₅-C₆. We examined the folding tendencies of two synthetic peptides corresponding to truncated versions of TM EGF-like domain four and five under air oxidation and redox folding conditions. By identifying the structural isoforms obtained in the folding reaction using regiospecifically-synthesized conformers as controls, we determined that the last segment of both domains (encompassing C₅ and C₆) do not influence the tendencies to fold into their respective native conformations. When folded under denaturing conditions, the folding tendency of the fourth EGF-like domain changes to that of the C₁-C₂, C₃-C₄ conformer. Conversely, the addition of denaturant did not affect the folding tendency of the fifth EGF-like domain. This suggests that side chain interactions are crucial for achieving the canonical EGF-like domain fold but not for the non-canonical fold. Folding under high salt content did not disrupt the folding tendencies of both domains and result in slight increase of the C₁-C₃, C₂-C₄ conformer in both cases. This suggests that hydrophobic interaction, but not electrostatic interaction, is the key in the achieving the canonical fold of EGF-like domains."]},{"key":"dc:format.checksum.md5","label":"Dc Format Checksum Md5","values":["01d121c5b895403c530f5fb091be02d9","67538bd76e11ce41370e582d80fc795a"]},{"key":"dc:title","label":"Title","values":["Structural Determinants in the folding of epidermal growth factor (EGF)-Like domains"]}]}],"canonical_facts":{"dc:creator":["NG AH SOCK ANGIE"],"dc:date.issued":["2011-01-11"],"dc:description.abstract":["The epidermal growth factor (EGF)-like domain is an evolutionarily conserved modular protein subunit. Despite hypervariability of amino acid sequences in their inter-cysteine region, they preferentially fold into a three-looped conformation with a disulfide pairing of C₁-C₃, C₂-C₄, C₅-C₆. To elucidate the structural determinants that dictates the canonical EGF-like domain fold, we had chosen the fourth and fifth EGF-like domain of thrombomodulin (TM) as models. While the fourth EGF-like domain folds into the canonical conformation, the fifth EGF-like domain does not and possesses an alternate disulfide pairing of C₁-C₂, C₃-C₄, C₅-C₆. We examined the folding tendencies of two synthetic peptides corresponding to truncated versions of TM EGF-like domain four and five under air oxidation and redox folding conditions. By identifying the structural isoforms obtained in the folding reaction using regiospecifically-synthesized conformers as controls, we determined that the last segment of both domains (encompassing C₅ and C₆) do not influence the tendencies to fold into their respective native conformations. When folded under denaturing conditions, the folding tendency of the fourth EGF-like domain changes to that of the C₁-C₂, C₃-C₄ conformer. Conversely, the addition of denaturant did not affect the folding tendency of the fifth EGF-like domain. This suggests that side chain interactions are crucial for achieving the canonical EGF-like domain fold but not for the non-canonical fold. Folding under high salt content did not disrupt the folding tendencies of both domains and result in slight increase of the C₁-C₃, C₂-C₄ conformer in both cases. This suggests that hydrophobic interaction, but not electrostatic interaction, is the key in the achieving the canonical fold of EGF-like domains."],"dc:format.checksum.md5":["01d121c5b895403c530f5fb091be02d9","67538bd76e11ce41370e582d80fc795a"],"dc:identifier.uri":["https://scholarbank.nus.edu.sg/bitstreams/31d31831-ad52-4102-9e0c-8b5061018051/download"],"dc:relation.isreferencedby":["https://scholarbank.nus.edu.sg/handle/10635/22764"],"dc:subject":["protein folding code, structural determinants, epidermal growth factor-like domains"],"dc:title":["Structural Determinants in the folding of epidermal growth factor (EGF)-Like domains"],"dc:type":["Thesis"]},"updated_at":"2026-07-24T03:32:43Z"}