Characterization of Structural, Dynamic and Functional Relationships of a Mutant Analogous from Mastoparan-B by NMR
| Autor: | Hsin-Ru Chang, 張馨如 |
|---|---|
| Rok vydání: | 2011 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 99 In Taiwan, the black-bellied hornet (vespa basalis) is certainly the most dangerous and most aggressive one in all kinds of vaspine wesp. Mastoparan-B (MP-B), a main component of the venom of black-bellied hornet, is a potent anti-bacteria peptide consisting of 14 amino acid residues (LKLKSIVSWAKKVL-NH2). Previous study had shown that hemolytic activity of MP-B is almost abolished as tryptophan at position 9 is mutated by phenylalanine. MP-B-9F, a mutant analogous at position 9 was mutated by phenylalanine, was synthesized by Solid Phase Peptide Synthesis (SPPS), purified by HPLC and checked the molecular weight of peptide by ESI-MASS. The structure has been characterized by CD and 2D-NMR spectroscopy. As comparing with MP-B, the α-helix content in MP-B-9F is less at 283K but is more stable as temperature increased. The structure was simulated by Xplor-nih, and shows that residues 5-8 adopt a helical conformation in 283K, 30% TFE/water mixture. The 13C relaxation parameters of MP-B and MP-B-9F were determined in 30% TFE/water mixture. The relaxation parameters, T1, T2, and NOE were analyzed using model-free approach. We calculated the order parameters, S2 and overall correlation times, τm of both peptides. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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