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

 

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dc.contributor.advisor Jackson, Graham Ellis en_ZA
dc.contributor.author Sunter, Katherine Margaret en_ZA
dc.date.accessioned 2016-03-07T06:56:47Z
dc.date.available 2016-03-07T06:56:47Z
dc.date.issued 1996 en_ZA
dc.identifier.citation Sunter, 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.uri http://hdl.handle.net/11427/17558
dc.description Includes bibliographical references. en_ZA
dc.description.abstract 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. en_ZA
dc.language.iso eng en_ZA
dc.subject.other Chemistry en_ZA
dc.title Secondary structure determination of insect neuropeptides using high-resolution nuclear magnetic resonance and various molecular mechanics calculations en_ZA
dc.type Master Thesis
uct.type.publication Research en_ZA
uct.type.resource Thesis en_ZA
dc.publisher.institution University of Cape Town
dc.publisher.faculty Faculty of Science en_ZA
dc.publisher.department Department of Chemistry en_ZA
dc.type.qualificationlevel Masters
dc.type.qualificationname MSc en_ZA
uct.type.filetype Text
uct.type.filetype Image
dc.identifier.apacitation Sunter, 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/11427/17558 en_ZA
dc.identifier.chicagocitation Sunter, 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/11427/17558 en_ZA
dc.identifier.vancouvercitation Sunter 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/11427/17558 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


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