Secondary structure determination of insect neuropeptides using high-resolution nuclear magnetic resonance and various molecular mechanics calculations

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dc.contributor.advisorJackson, Graham Ellisen_ZA
dc.contributor.authorSunter, Katherine Margareten_ZA
dc.date.accessioned2016-03-07T06:56:47Z
dc.date.available2016-03-07T06:56:47Z
dc.date.issued1996en_ZA
dc.descriptionIncludes bibliographical references.en_ZA
dc.description.abstractInsect neuropeptides play a vital role in the hormone release processes associated with insect flight Elucidation of the metabolic flight pathways requires a knowledge of the peptide secondary structure to allow predictions to be made regarding hormone-receptor binding processes. The three insect neuropeptides under investigation were taken from the corpora cardiaca of the migratory locust (Locusta migratoria) and belonged to the Lom peptide series - Lom-AKH-I, II and Ill. The secondary structure of these hormones was investigated using high-resolution nuclear magnetic resonance (NMR) techniques and various molecular mechanics computations. The interproton distances and φ torsion angles obtained from the NMR data were used to constrain the peptides in subsequent Monte Carlo and molecular dynamics (simulated annealing) calculations. The results of these calculations indicated that Lom-AKH-I and Lom-AKH-III adopt a definite structure in d⁶-DMSO solution, while Lom-AKH-II appeared to be fluctional with a minimum of three structures being required to satisfy the experimental data. Lom-AKH-I and ill were shown to adopt a loose open turn structures stabilised by the presence of a single hydrogen bond. Both had an additional concave structure with hydrophobic clustering on the convex surface of the molecule. The results suggest that Lom-AKH-I and Lom-AKH-III are more reactive than Lom-AKH-II. These predictions are in agreement with literature results obtained for Lom-AKH-I and II for lipid mobilisation and phosphorylase activation. However, when measured against cAMP production, Lom-AKH-II has higher activity. Insufficient literature was available to make structure/activity comparisons for Lom-AKH-III.en_ZA
dc.identifier.apacitationSunter, K. M. (1996). <i>Secondary structure determination of insect neuropeptides using high-resolution nuclear magnetic resonance and various molecular mechanics calculations</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Chemistry. Retrieved from http://hdl.handle.net/11427/17558en_ZA
dc.identifier.chicagocitationSunter, Katherine Margaret. <i>"Secondary structure determination of insect neuropeptides using high-resolution nuclear magnetic resonance and various molecular mechanics calculations."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Chemistry, 1996. http://hdl.handle.net/11427/17558en_ZA
dc.identifier.citationSunter, K. 1996. Secondary structure determination of insect neuropeptides using high-resolution nuclear magnetic resonance and various molecular mechanics calculations. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Sunter, Katherine Margaret AB - Insect neuropeptides play a vital role in the hormone release processes associated with insect flight Elucidation of the metabolic flight pathways requires a knowledge of the peptide secondary structure to allow predictions to be made regarding hormone-receptor binding processes. The three insect neuropeptides under investigation were taken from the corpora cardiaca of the migratory locust (Locusta migratoria) and belonged to the Lom peptide series - Lom-AKH-I, II and Ill. The secondary structure of these hormones was investigated using high-resolution nuclear magnetic resonance (NMR) techniques and various molecular mechanics computations. The interproton distances and φ torsion angles obtained from the NMR data were used to constrain the peptides in subsequent Monte Carlo and molecular dynamics (simulated annealing) calculations. The results of these calculations indicated that Lom-AKH-I and Lom-AKH-III adopt a definite structure in d⁶-DMSO solution, while Lom-AKH-II appeared to be fluctional with a minimum of three structures being required to satisfy the experimental data. Lom-AKH-I and ill were shown to adopt a loose open turn structures stabilised by the presence of a single hydrogen bond. Both had an additional concave structure with hydrophobic clustering on the convex surface of the molecule. The results suggest that Lom-AKH-I and Lom-AKH-III are more reactive than Lom-AKH-II. These predictions are in agreement with literature results obtained for Lom-AKH-I and II for lipid mobilisation and phosphorylase activation. However, when measured against cAMP production, Lom-AKH-II has higher activity. Insufficient literature was available to make structure/activity comparisons for Lom-AKH-III. DA - 1996 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1996 T1 - Secondary structure determination of insect neuropeptides using high-resolution nuclear magnetic resonance and various molecular mechanics calculations TI - Secondary structure determination of insect neuropeptides using high-resolution nuclear magnetic resonance and various molecular mechanics calculations UR - http://hdl.handle.net/11427/17558 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/17558
dc.identifier.vancouvercitationSunter KM. Secondary structure determination of insect neuropeptides using high-resolution nuclear magnetic resonance and various molecular mechanics calculations. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Chemistry, 1996 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/17558en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Chemistryen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherChemistryen_ZA
dc.titleSecondary structure determination of insect neuropeptides using high-resolution nuclear magnetic resonance and various molecular mechanics calculationsen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMScen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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