Structural similarity of a membrane protein in micelles and membranes

Sanford-Burnham Medical Research Institute, لا هویا, California, United States
Journal of the American Chemical Society (Impact Factor: 11.44). 08/2007; 129(26):8078-9. DOI: 10.1021/ja0728371
Source: PubMed

ABSTRACT The anisotropic spin interactions measured for membrane proteins in weakly oriented micelles and in oriented lipid bilayers provide independent and potentially complementary high-resolution restraints for structure determination. Here we show that the membrane protein CHIF adopts a similar structure in lipid micelles and bilayers, allowing the restraints from micelle and bilayer samples to be combined in a complementary fashion to enhance the structural information. Back-calculation and assignment of the NMR spectrum of CHIF in oriented lipid bilayers, from the structure determined in micelles, provides additional restraints for structure determination as well as the global orientation of the protein in the membrane. The combined use of solution and solid-state NMR restraints also affords cross-validation for the structural analysis.

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Available from: Peter Teriete, Aug 16, 2015
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    • "e l s e v i e r . c o m / l o c a t e / b b a m e m experiments have shown that native protein quaternary structure may be maintained in detergent environments [18] [19]; aspects of secondary and tertiary structure may be similar in lipid bilayer versus micelle environments [20]; and the overall fold of a protein may persist in detergents [21]. We have recently observed that the interaction of designed TM segments with detergents is highly sequencedependent , and in many cases mimics the predicted in vivo formation of both helix–helix and protein–lipid interactions [22] [23]. "
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    Biochimica et Biophysica Acta 01/2012; 1818(5):1351-8. DOI:10.1016/j.bbamem.2012.01.013 · 4.66 Impact Factor
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    • "The HSQC spectrum of 15 N labeled SH protein was tested in three detergents: DPC (medium-chain, zwitterionic), DHPC (short-chain, zwitterionic), and SDS (anionic) (Fig. 8). Although SDS is a harsh detergent, well-resolved spectra of membrane proteins have been recorded (Howell et al., 2005; Franzin et al., 2007; Teriete et al., 2007). In contrast, DPC and DHPC have a headgroup that closely mimics that of phosphatidylcholine, the most abundant headgroup in natural membranes, successfully used in KcsA (Yu et al., 2005), human phospholamban (Oxenoid & Chou, 2005), diacylglycerol kinase (Van Horn et al., 2009), Rv1761c from Mycobacterium tuberculosis (Page et al., 2009), influenza A M2 (Schnell & Chou, 2008) or HIV Vpu (Park et al., 2003). "
    Human Respiratory Syncytial Virus Infection, 11/2011; , ISBN: 978-953-307-718-5
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    • "Recently, we determined the NMR structure of non-phosphorylated FXYD1 in detergent micelles [27]. The N-terminal transmembrane domain forms three rigidly connected helices (h1, h2, h3) and shares both significant amino acid sequence homology [5] as well as structural similarity [6] [28] with the other FXYD proteins (Fig. 1). It is loosely connected to a 10-residue C-terminal cytoplasmic helix (h4) with a sequence unique to FXYD1, which contains the phosphorylation domain. "
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    ABSTRACT: FXYD1 (phospholemman) is a member of an evolutionarily conserved family of membrane proteins that regulate the function of the Na,K-ATPase enzyme complex in specific tissues and specific physiological states. In heart and skeletal muscle sarcolemma, FXYD1 is also the principal substrate of hormone-regulated phosphorylation by c-AMP dependent protein kinase A and by protein kinase C, which phosphorylate the protein at conserved Ser residues in its cytoplasmic domain, altering its Na,K-ATPase regulatory activity. FXYD1 adopts an L-shaped α-helical structure with the transmembrane helix loosely connected to a cytoplasmic amphipathic helix that rests on the membrane surface. In this paper we describe NMR experiments showing that neither PKA phosphorylation at Ser68 nor the physiologically relevant phosphorylation mimicking mutation Ser68Asp induces major changes in the protein conformation. The results, viewed in light of a model of FXYD1 associated with the Na,K-ATPase α and β subunits, indicate that the effects of phosphorylation on the Na,K-ATPase regulatory activity of FXYD1 could be due primarily to changes in electrostatic potential near the membrane surface and near the Na+/K+ ion binding site of the Na,K-ATPase α subunit.
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