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- | [[Image:1f0h.jpg|left|200px]] | + | {{Seed}} |
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| {{STRUCTURE_1f0h| PDB=1f0h | SCENE= }} | | {{STRUCTURE_1f0h| PDB=1f0h | SCENE= }} |
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- | '''Cecropin A(1-8)-magainin 2(1-12) A2 in dodecylphosphocholine micelles'''
| + | ===Cecropin A(1-8)-magainin 2(1-12) A2 in dodecylphosphocholine micelles=== |
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- | ==Overview==
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- | A 20-residue hybrid peptide CA(1-8)-MA(1-12) (CA-MA), incorporating residues 1-8 of cecropin A (CA) and residues 1-12 of magainin 2 (MA), has potent antimicrobial activity without toxicity against human erythrocytes. To investigate the effects of the Gly-Ile-Gly hinge sequence of CA-MA on the antibacterial and antitumor activities, two analogues in which the Gly-Ile-Gly sequence of CA-MA is either deleted (P1) or substituted with Pro (P2) were synthesized. The role of the tryptophan residue at position 2 of CA-MA on its antibiotic activity was also investigated using two analogues, in which the Trp2 residue of CA-MA is replaced with either Ala (P3) or Leu (P4). The tertiary structures of CA-MA, P2, and P4 in DPC micelles, as determined by NMR spectroscopy, have a short amphiphilic helix in the N-terminus and about three turns of alpha-helix in the C-terminus, with the flexible hinge region between them. The P1 analogue has an alpha-helix from Leu4 to Ala14 without any hinge structure. P1 has significantly decreased lytic activities against bacterial and tumor cells and PC/PS vesicles (3:1, w/w), and reduced pore-forming activity on lipid bilayers, while P2 retained effective lytic activities and pore-forming activity. The N-terminal region of P3 has a flexible structure without any specific secondary structure. The P3 modification caused a drastic decrease in the antibiotic activities, whereas P4, with the hydrophobic Leu side chain at position 2, retained its activities. On the basis of the tertiary structures, antibiotic activities, vesicle-disrupting activities, and pore-forming activities, the structure-function relationships can be summarized as follows. The partial insertion of the Trp2 of CA-MA into the membrane, as well as the electrostatic interactions between the positively charged Lys residues at the N-terminus of the CA-MA and the anionic phospholipid headgroups, leads to the primary binding to the cell membrane. Then, the flexibility or bending potential induced by the Gly-Ile-Gly hinge sequence or the Pro residue in the central part of the peptides may allow the alpha-helix in the C-terminus to span the lipid bilayer. These structural features are crucial for the potent antibiotic activities of CA-MA.
| + | The line below this paragraph, {{ABSTRACT_PUBMED_11009597}}, adds the Publication Abstract to the page |
| + | (as it appears on PubMed at http://www.pubmed.gov), where 11009597 is the PubMed ID number. |
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| + | {{ABSTRACT_PUBMED_11009597}} |
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| ==About this Structure== | | ==About this Structure== |
- | 1F0H is a [[Single protein]] structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1F0H OCA]. | + | 1F0H is a [[Single protein]] structure. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1F0H OCA]. |
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| ==Reference== | | ==Reference== |
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| [[Category: Shin, S Y.]] | | [[Category: Shin, S Y.]] |
| [[Category: Helix]] | | [[Category: Helix]] |
- | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 15:44:39 2008'' | + | |
| + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 1 02:17:49 2008'' |
Revision as of 23:17, 30 June 2008
Template:STRUCTURE 1f0h
Cecropin A(1-8)-magainin 2(1-12) A2 in dodecylphosphocholine micelles
Template:ABSTRACT PUBMED 11009597
About this Structure
1F0H is a Single protein structure. Full experimental information is available from OCA.
Reference
Role of the hinge region and the tryptophan residue in the synthetic antimicrobial peptides, cecropin A(1-8)-magainin 2(1-12) and its analogues, on their antibiotic activities and structures., Oh D, Shin SY, Lee S, Kang JH, Kim SD, Ryu PD, Hahm KS, Kim Y, Biochemistry. 2000 Oct 3;39(39):11855-64. PMID:11009597
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