1afh
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LIPID TRANSFER PROTEIN FROM MAIZE SEEDLINGS, NMR, 15 STRUCTURES
OverviewOverview
The three-dimensional solution structure of a nonspecific lipid transfer, protein extracted from maize seeds determined by 1H NMR spectroscopy is, described. This cationic protein consists of 93 amino acid residues. Its, structure was determined from 1,091 NOE-derived distance restraints, including 929 interresidue connectivities and 197 dihedral restraints, (phi, psi, chi 1) derived from NOEs and 3J coupling constants. The global, fold involving four helical fragments connected by three loops and a, C-terminal tail without regular secondary structures is stabilized by four, disulfide bridges. The most striking feature of this structure is the, existence of an internal hydrophobic cavity running through the whole, molecule. The global fold of this protein, very similar to that of a, previously described lipid transfer protein extracted from wheat seeds, (Gincel E et al., 1994, Eur J Biochem 226:413-422) constitutes a new, architecture for alpha-class proteins. 1H NMR and fluorescence studies, show that this protein forms well-defined complexes in aqueous solution, with lysophosphatidylcholine. Dissociation constants, Kd, of 1.9 +/- 0.6 x, 10(-6) M and > 10(-3) M were obtained with lyso-C16 and -C12, respectively. A structure model for a lipid-protein complex is proposed in, which the aliphatic chain of the phospholipid is inserted in the internal, cavity and the polar head interacts with the charged side chains located, at one end of this cavity. Our model for the lipid-protein complex is, qualitatively very similar to the recently published crystal structure, (Shin DH et al., 1995, Structure 3:189-199).
About this StructureAbout this Structure
1AFH is a Single protein structure of sequence from Zea mays. Full crystallographic information is available from OCA.
ReferenceReference
Solution structure and lipid binding of a nonspecific lipid transfer protein extracted from maize seeds., Gomar J, Petit MC, Sodano P, Sy D, Marion D, Kader JC, Vovelle F, Ptak M, Protein Sci. 1996 Apr;5(4):565-77. PMID:8845747
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