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: 12.11). 08/2007; 129(26):8078-9. DOI: 10.1021/ja0728371
Source: PubMed


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.

    • "CD4 Ubiquitin PreScission pTKK19xb/ub 2KLU [132] TM of APP - Thrombin - 2LOH [48] Glycophorin A Staphylococcal nucle- ase Trypsin pT7SN DPC 1AFO [40] Stannin Maltose-binding protein Thrombin pMal-c2x 1ZZA [133] GP41 Ketosteroid isomerase Asp-Pro site pET31b 2ARI [134] M13 coat protein - - - 2CPS [135] Sarcolipin Synthesized - - 1JDM [136] FXYD4 Bcl-xL CNBr pBCL 2JP3 [137] "
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    ABSTRACT: Membrane proteins play important roles in signal transduction across the cell membrane. Structural information for the membrane proteins is still limited due to many technical challenges. Membrane proteins containing a single α- helical transmembrane (TM) domain are very important in several pathways. Solution NMR spectroscopy is an important tool for the study of the structure of the TM domain of these types of proteins due to their small size. In this review, we summarize the importance of some single-span membrane proteins in signal transduction and the importance of understanding the structure of the TM domain. We discussed the current progress in the structural study of these types of proteins using solution NMR spectroscopy. We summarize the structures solved during last several years. The structures of the regulatory domain of the ion channels such as KCNE1, integrin and viral proteins such as the M2 channel are described. The binding interface of single TM-TM domains is discussed based on NMR structural studies. Strategies including sample preparation, detergent screening, and structural determination of single-span membrane protein are summarized. We also discuss the potential application of NMR spectroscopy to drug discovery of proteins with a single-span TM domain.
    No preview · Article · Oct 2012 · Current Protein and Peptide Science
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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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    ABSTRACT: High-resolution structural analysis of membrane proteins by X-ray crystallography or solution NMR spectroscopy often requires their solubilization in the membrane-mimetic environments of detergents. Yet the choice of a detergent suitable for a given study remains largely empirical. In the present work, we considered the micelle-crystallized structures of lactose permease (LacY), the sodium/galactose symporter (vSGLT), the vitamin B(12) transporter (BtuCD), and the arginine/agmatine antiporter (AdiC). Representative transmembrane (TM) segments were selected from these proteins based on their relative contact(s) with water, lipid, and/or within the protein, and were synthesized as Lys-tagged peptides. Each peptide was studied by circular dichroism and fluorescence spectroscopy in water, and in the presence of the detergents sodium dodecylsulfate (SDS, anionic); n-dodecyl phosphatidylcholine (DPC, zwitterionic); n-dodecyl-β-d-maltoside (DDM, neutral); and n-octyl-β-d-glucoside (OG, neutral, varying acyl tail length). We found that (i) the secondary structures of the TM segments were statistically indistinguishable in the four detergents studied; and (ii) a strong correlation exists between the extent of helical structure of each individual TM segment in detergents with its helicity level as it exists in the full-length protein, indicating that helix adoption is fundamentally the same in both environments. The denaturing properties of so-called 'harsh' detergents may thus largely be due to their interactions with non-membranous regions of proteins. Given the consistency of structural features observed for each TM segment in a variety of micellar media, the overall results suggest that the structure likely corresponds to its relevant biological form in the intact protein in its native lipid bilayer environment.
    Full-text · Article · Jan 2012 · Biochimica et Biophysica Acta
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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). "

    Full-text · Chapter · Nov 2011
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