How Do Lipids Affect the Structure and Function of Integral Membrane Proteins

AbstractCellular membranes and associated proteins play critical physiological roles in organisms from all life kingdoms. In many cases, malfunction of biological membranes triggered by changes in the lipid bilayer properties or membrane protein functional abnormalities lead to severe diseases. To understand in detail the processes that govern the life of cells and to control diseases, one of the major tasks in biological sciences is to learn how the membrane proteins function. To do so, a variety of biochemical and biophysical approaches have been used in molecular studies of membrane protein structure and function on the nanoscale. This review focuses on electron paramagnetic resonance with site-directed nitroxide spin-labeling (SDSL EPR), which is a rapidly expanding and powerful technique reporting on the local protein/spin-label dynamics and on large functionally important structural rearrangements. On the other hand, adequate to nanoscale study membrane mimetics have been developed and used in conjunction with SDSL EPR. Primarily, these mimetics include various liposomes, bicelles, and nanodiscs. This review provides a basic description of the EPR methods, continuous-wave and pulse, applied to spin-labeled proteins, and highlights several representative applications of EPR to liposome-, bicelle-, or nanodisc-reconstituted membrane proteins.

Download Full-text

Bioinformatic approaches for the structure and function of membrane proteins

BMB Reports ◽

10.5483/bmbrep.2009.42.11.697 ◽

2009 ◽

Vol 42 (11) ◽

pp. 697-704 ◽

Cited By ~ 17

Author(s):

Hyun-Jun Nam ◽

Jou-Hyun Jeon ◽

Sang-Uk Kim

Keyword(s):

Membrane Proteins ◽

Structure And Function ◽

Bioinformatic Approaches ◽

And Function

Download Full-text

Structure and function of qiuinone binding membrane proteins

Membrane Proteins - Advances in Protein Chemistry ◽

10.1016/s0065-3233(03)63007-x ◽

2003 ◽

pp. 151-176 ◽

Cited By ~ 3

Author(s):

Momi Iwata ◽

Jeff Abramson ◽

Bernadette Byrne ◽

S.O Iwata

Keyword(s):

Membrane Proteins ◽

Structure And Function ◽

And Function

Download Full-text

Biophysical methods toolbox to study ABC exporter structure and function

Biological Chemistry ◽

10.1515/hsz-2016-0244 ◽

2017 ◽

Vol 398 (2) ◽

pp. 229-235

Author(s):

Thomas Marcellino ◽

Vasundara Srinivasan

Keyword(s):

Membrane Proteins ◽

Abc Transporter ◽

Integrated Approach ◽

Structure And Function ◽

Dynamic Membrane ◽

Biophysical Characterization ◽

Intermediate States ◽

And Function

Abstract ABC exporters are highly dynamic membrane proteins that span a huge spectrum of different conformations. A detailed integrated approach of cellular, biochemical and biophysical characterization of these ‘open’, ‘closed’ and other intermediate states is central to understanding their function. Almost 40 years after the discovery of the first ABC transporter, thanks to the enormous development in methodologies, a picture is slowly emerging to visualize how these fascinating molecules transport their substrates. This mini review summarizes some of the biophysical tools that have made a major impact in understanding the function of the ABC exporters.

Download Full-text

Bacterial ß-Barrel Outer Membrane Proteins

Handbook of Research on Systems Biology Applications in Medicine ◽

10.4018/978-1-60566-076-9.ch010 ◽

2009 ◽

pp. 182-207

Author(s):

Pantelis G. Bagos ◽

Stavros J. Hamodrakas

Keyword(s):

Membrane Proteins ◽

Outer Membrane ◽

Bacterial Cell ◽

Outer Membrane Proteins ◽

Structural Features ◽

Structure And Function ◽

Structural Motif ◽

Functional Roles ◽

Bacterial Outer Membrane ◽

And Function

ß-barrel outer membrane proteins constitute the second and less well-studied class of transmembrane proteins. They are present exclusively in the outer membrane of Gram-negative bacteria and presumably in the outer membrane of mitochondria and chloroplasts. During the last few years, remarkable advances have been made towards an understanding of their functional and structural features. It is now wellknown that ß-barrels are performing a large variety of biologically important functions for the bacterial cell. Such functions include acting as specific or non-specific channels, receptors for various compounds, enzymes, translocation channels, structural proteins, and adhesion proteins. All these functional roles are of great importance for the survival of the bacterial cell under various environmental conditions or for the pathogenic properties expressed by these organisms. This chapter reviews the currently available literature regarding the structure and function of bacterial outer membrane proteins. We emphasize the functional diversity expressed by a common structural motif such as the ß-barrel, and we provide evidence from the current literature for dozens of newly discovered families of transmembrane ß-barrels.

Download Full-text

Membrane proteins: is the future disc shaped?

Biochemical Society Transactions ◽

10.1042/bst20160015 ◽

2016 ◽

Vol 44 (4) ◽

pp. 1011-1018 ◽

Cited By ~ 24

Author(s):

Sarah C. Lee ◽

Naomi L. Pollock

Keyword(s):

Membrane Proteins ◽

Maleic Acid ◽

Membrane Lipids ◽

Biological Membranes ◽

Structure And Function ◽

Amphiphilic Copolymer ◽

New Approach ◽

Analysis Techniques ◽

Lipid Particles ◽

And Function

The use of styrene maleic acid lipid particles (SMALPs) for the purification of membrane proteins (MPs) is a rapidly developing technology. The amphiphilic copolymer of styrene and maleic acid (SMA) disrupts biological membranes and can extract membrane proteins in nanodiscs of approximately 10 nm diameter. These discs contain SMA, protein and membrane lipids. There is evidence that MPs in SMALPs retain their native structures and functions, in some cases with enhanced thermal stability. In addition, the method is compatible with biological buffers and a wide variety of biophysical and structural analysis techniques. The use of SMALPs to solubilize and stabilize MPs offers a new approach in our attempts to understand, and influence, the structure and function of MPs and biological membranes. In this review, we critically assess progress with this method, address some of the associated technical challenges, and discuss opportunities for exploiting SMA and SMALPs to expand our understanding of MP biology.

Download Full-text