Solution Structure of Ace-AMP1, a Potent Antimicrobial Protein Extracted from Onion Seeds. Structural Analogies with Plant Nonspecific Lipid Transfer Proteins
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- 作者：Sé ; verine Tassin ; Willem F. Broekaert ; Didier Marion ; David P. Acland ; Marius Ptak ; Franç ; oise Vovelle ; and Patrick Sodano
- 刊名：Biochemistry
- 出版年：1998
- 出版时间：March 17, 1998
- 年：1998
- 卷：37
- 期：11
- 页码：3623 - 3637
- 全文大小：292K
- 年卷期：v.37,no.11(March 17, 1998)
- ISSN：1520-4995
文摘
The three-dimensional solution structure of Ace-AMP1,an antifungal protein extracted fromonion seeds, was determined using 1H NMR spectroscopy andmolecular modeling. This cationic proteincontains 93 amino acid residues and four disulfide bridges. Itsstructure was determined from 1260 NOE-derived distance restraints and 173 dihedral restraints derived fromNOEs and3JCaHNHcoupling constants.The global fold involves four helical segments connected by threeloops and a C-terminal tail withoutregular secondary structures, except for a 310-helix turnand a 
-turn. The most striking feature is theabsence of any continuous cavity running through the whole molecule asfound in recently determinedstructures of nonspecific transfer proteins extracted from wheat andmaize seeds, although their globalfolds are very similar. Consistent with the absence of a cavity inthe core of Ace-AMP1, it was foundthat this protein, in contrast to ns-LTPs, does not bind fluorescentlylabeled phospholipids in solution.On the other hand, Ace-AMP1 is able to interact withphospholipid membranes as shown by the releaseof carboxyfluorescein from the lumen of artificial liposomes and by theinduction of alterations influorescence polarization of fluorescently labeled phospholipidsembedded in artificial liposomes.
-turn. The most striking feature is theabsence of any continuous cavity running through the whole molecule asfound in recently determinedstructures of nonspecific transfer proteins extracted from wheat andmaize seeds, although their globalfolds are very similar. Consistent with the absence of a cavity inthe core of Ace-AMP1, it was foundthat this protein, in contrast to ns-LTPs, does not bind fluorescentlylabeled phospholipids in solution.On the other hand, Ace-AMP1 is able to interact withphospholipid membranes as shown by the releaseof carboxyfluorescein from the lumen of artificial liposomes and by theinduction of alterations influorescence polarization of fluorescently labeled phospholipidsembedded in artificial liposomes.