Biochemistry of Lipids, Lipoproteins and Membranes (eBook)

Roger McLeod, Neale Ridgway (Herausgeber)

eBook Download: PDF | EPUB

2015 | 6. Auflage
612 Seiten
Elsevier Science (Verlag)
978-0-444-63449-8 (ISBN)

Biochemistry of Lipids: Lipoproteins and Membranes, Volume Six, contains concise chapters that cover a wide spectrum of topics in the field of lipid biochemistry and cell biology. It provides an important bridge between broad-based biochemistry textbooks and more technical research publications, offering cohesive, foundational information. It is a valuable tool for advanced graduate students and researchers who are interested in exploring lipid biology in more detail, and includes overviews of lipid biology in both prokaryotes and eukaryotes, while also providing fundamental background on the subsequent descriptions of fatty acid synthesis, desaturation and elongation, and the pathways that lead the synthesis of complex phospholipids, sphingolipids, and their structural variants. Also covered are sections on how bioactive lipids are involved in cell signaling with an emphasis on disease implications and pathological consequences. - Serves as a general reference book for scientists studying lipids, lipoproteins and membranes and as an advanced and up-to-date textbook for teachers and students who are familiar with the basic concepts of lipid biochemistry - References from current literature will be included in each chapter to facilitate more in-depth study - Key concepts are supported by figures and models to improve reader understanding - Chapters provide historical perspective and current analysis of each topic

Biochemistry of Lipids: Lipoproteins and Membranes, Volume Six, contains concise chapters that cover a wide spectrum of topics in the field of lipid biochemistry and cell biology. It provides an important bridge between broad-based biochemistry textbooks and more technical research publications, offering cohesive, foundational information. It is a valuable tool for advanced graduate students and researchers who are interested in exploring lipid biology in more detail, and includes overviews of lipid biology in both prokaryotes and eukaryotes, while also providing fundamental background on the subsequent descriptions of fatty acid synthesis, desaturation and elongation, and the pathways that lead the synthesis of complex phospholipids, sphingolipids, and their structural variants. Also covered are sections on how bioactive lipids are involved in cell signaling with an emphasis on disease implications and pathological consequences. - Serves as a general reference book for scientists studying lipids, lipoproteins and membranes and as an advanced and up-to-date textbook for teachers and students who are familiar with the basic concepts of lipid biochemistry- References from current literature will be included in each chapter to facilitate more in-depth study- Key concepts are supported by figures and models to improve reader understanding- Chapters provide historical perspective and current analysis of each topic

Chapter 2

Approaches to Lipid Analysis

Jeff G. McDonald1, Pavlina T. Ivanova2, and H. Alex Brown2,3 1Department of Molecular Genetics, UT Southwestern Medical Center, Dallas, TX, USA 2Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA 3Department of Biochemistry and The Vanderbilt Institute of Chemical Biology, Vanderbilt University School of Medicine, Nashville, TN, USA

Abstract

Historically, lipids have been defined in many ways, but at the most elementary level, they are biologically derived molecules soluble in organic solvents. Lipid species include chemical entities that are among the fundamental building blocks of life. The chemical and structural heterogeneity of lipids contributes to innumerable biochemical and biophysical processes and thereby presents challenges in analysis. Advances in chromatography, mass spectrometry and computational biology have enabled the progression of lipidomics within the larger field of analytical chemistry. Advancements in mass spectrometry-based lipid analysis have contributed to remarkable discoveries in both basic and translational research and any well-conducted study of biological processes involving lipids is now expected to include lipidomic analysis. In this chapter we introduce readers to the basic concepts of identification and measurements of lipid species that constitute the modern field of lipidomics.

Keywords

Lipidomics; Mass spectrometry; Phospholipids; Sterols

Abbreviations

Electron ionisation

Gas chromatography

HPLC

High-performance liquid chromatography

LLE

Liquid–liquid extraction

Mass spectrometry

NIST

National Institute of Standards and Technology

TAG

Triacylglycerol

TLC

Thin-layer chromatography

RRF

Relative response factor

TMAO

Trimethylamine-N-oxide

1. Introduction and Overview

Lipids are among the fundamental building blocks of life. Simple ancient organisms living in the preoxidising environment likely used hydrocarbon chains and pentacyclic ring sterol-like compounds to evolve the huge diversity of complex structures that constitute the rich array of fats found throughout the tree of life. These molecules have remarkable chemical and structural heterogeneity that contributes to innumerable biochemical and biophysical processes.

That organic oils (a mixture of chemicals composed largely of fatty acids and triacylglycerols (TAGs)) are precious and valuable commodities have been recognised by humans for thousands of years. This value justifies the classification and careful measurement of these compounds. The analysis of lipids by mass spectrometry (MS) has been performed for decades, but a systems biology-based analysis that monitors changes in many lipid analytes in parallel has its beginnings in the early part of the current century. As elegantly defined by McLafferty and Tureček (1993), ‘The mass spectrum shows the mass of the molecule and the masses of the pieces from it’. This is the fundamental basis for the analysis of lipids by MS just as for other small molecule analytes. The mass spectrum of a lipid does not reveal the precise chemical structure of the molecular species, but its systematic fragmentation gives information about the chemical arrangement. For precise determination of the structures of unknown lipids, a combination of MS with other techniques, such as nuclear magnetic resonance, is required.

2. Lipid Diversity

Lipids have many definitions but, in simplest terms, are biologically relevant molecules that are soluble in organic solvents (major lipid classes and their metabolic origins are shown in Figure 1). They include a wide variety of chemical entities such as fatty acids and their derivatives, sterols and steroids and isoprenoids. Fatty acid moieties can be esterified to alcohols, forming glycerol-based lipids like TAGs (Chapters 5 and 6), or be linked by an amide bond to long-chain bases, forming sphingolipids (Chapter 10). Each of these lipids can also contain phosphoric acid, forming the phospholipid category (Chapters 3 and 7). Some lipids are a source of energy in biological systems, while others serve as building blocks and major participants in cellular recognition and signal transduction across the cell membrane. This vast diversity in structure reflects the unique amphiphilic property of lipids imparted by their hydrophobic acyl chains and hydrophilic head groups. Lipids can generally be divided into three categories – fatty acids, simple lipids and complex lipids. Fatty acids from plant and animal origin have different properties. Fatty acids of animal origin are summarised in several subcategories – cis/trans, saturated, mono- or polyunsaturated. Plant fatty acids are more complex and may contain different functionalities, including epoxy-, hydroxy- and keto- groups. Bacterial fatty acids can contain branched, odd-carbon or cyclopropane groups (the synthesis and metabolism of these fatty acids is described in Chapters 3–6). Simple lipids only contain fatty acids and alcohol constituents. The alcohol can be glycerol, esterified on one, two or all three hydroxyl groups, sterols or a long-chain alcohol. They are represented in triacyl-, diacyl- or monoacylglycerols, cholesterols and cholesteryl esters and wax esters. Complex lipids include glycoglycerolipids, glycerophospholipids and sphingolipids that are the major phospholipids present in mammalian cells. The comprehensive analysis of lipids generally involves separation into simpler categories, according to their chemical nature and identification and eventual quantitative measurement of a specific class, subclass or individual lipid (Hanahan, 1997).

Figure 1 Human lipid diversity.

Relationships among the major mammalian lipid categories are shown starting with the 2-carbon precursor acetyl-CoA, which is the building block in the biosynthesis of fatty acids. Fatty acyl substituents in turn are transferred to be part of the complex lipids, namely sphingolipids, glycerolipids, glycerophospholipids and sterols (as sterol esters). Fatty acids are also converted to eicosanoids. A second major biosynthetic route from acetyl-CoA generates the 5-carbon isoprene precursor isopentenyl pyrophosphate, which provides the building blocks for the prenol and sterol lipids. Fatty acyl-derived substituents are coloured green; isoprene-derived atoms are coloured purple; glycerol and serine-derived groups are coloured orange and blue, respectively. Arrows denote multistep transformations among the major lipid categories starting with acetyl-CoA. This figure and legend are modified from the original that appeared in Quehenberger et al. (2010), © the American Society for Biochemistry and Molecular Biology.

3. Chromatographic-Based Analysis of Lipids

3.1. Historical Perspective

The identification of lipids by chemical analysis dates back more than two centuries. Excellent timelines and historical perspectives of lipid science can be found throughout this book and elsewhere on the development of MS-based techniques (Brügger et al., 1997; Ivanova et al., 2001; Murphy et al., 2001; Han and Gross, 1995; Brown and Murphy, 2009). Detailed reports of methodologies for lipid measurements can be found dating back more than a century. These include the first mention of colourimetric assays, column chromatography and thin-layer chromatography (TLC). The introduction of spectrophotometric techniques provided additional insight for lipid researchers. Although modern versions of these tools are still employed in today’s laboratories, there have been considerable advances made in the quantitative measurement of lipids. Advances in chromatography, the advent of modern electronics (especially computers) and breakthroughs in gas-phase ionisation have dramatically expanded the tools for lipid analysis. A detailed explanation of the technical aspects of lipid MS from one of the pioneers of the lipid biochemistry field, Robert Murphy (1993), provides insightful explanations of collision-induced dissociation, ionisation techniques and other important details for the analysis of major lipid classes as well as interesting comments regarding the history and development of lipid analysis by MS.

3.2. Lipid Extraction from Biological Sources

Extraction of lipids from biological samples (e.g. cells, tissues, fluids) is the first step in any lipid analysis. An extraction begins when organic solvents are used to solubilise and separate the lipids from proteins, which are largely insoluble in these solvents. If necessary, the choice of extraction solvent can be tailored to a specific class of lipids (e.g. sphingolipids, phospholipids, lysophospholipids, phosphoinositides). In addition to solubilising lipids, solvents can serve to inactivate enzymes and denature proteins that would otherwise degrade or modify the extracted lipids. Solvent extraction will also help minimise the oxidation of polyunsaturated fatty acids. For these reasons, lipids are typically extracted from fluids, tissues or cultured cells soon after their removal or isolation....

Erscheint lt. Verlag	24.7.2015
Sprache	englisch
Themenwelt	Naturwissenschaften ► Biologie ► Biochemie
	Naturwissenschaften ► Biologie ► Zellbiologie
	Naturwissenschaften ► Physik / Astronomie ► Angewandte Physik
	Technik
ISBN-10	0-444-63449-5 / 0444634495
ISBN-13	978-0-444-63449-8 / 9780444634498

Haben Sie eine Frage zum Produkt?

PDF (Adobe DRM)
Größe: 23,2 MB

Kopierschutz: Adobe-DRM
Adobe-DRM ist ein Kopierschutz, der das eBook vor Mißbrauch schützen soll. Dabei wird das eBook bereits beim Download auf Ihre persönliche Adobe-ID autorisiert. Lesen können Sie das eBook dann nur auf den Geräten, welche ebenfalls auf Ihre Adobe-ID registriert sind.
Details zum Adobe-DRM

Dateiformat: PDF (Portable Document Format)
Mit einem festen Seitenlayout eignet sich die PDF besonders für Fachbücher mit Spalten, Tabellen und Abbildungen. Eine PDF kann auf fast allen Geräten angezeigt werden, ist aber für kleine Displays (Smartphone, eReader) nur eingeschränkt geeignet.

Systemvoraussetzungen:
PC/Mac: Mit einem PC oder Mac können Sie dieses eBook lesen. Sie benötigen eine Adobe-ID und die Software Adobe Digital Editions (kostenlos). Von der Benutzung der OverDrive Media Console raten wir Ihnen ab. Erfahrungsgemäß treten hier gehäuft Probleme mit dem Adobe DRM auf.
eReader: Dieses eBook kann mit (fast) allen eBook-Readern gelesen werden. Mit dem amazon-Kindle ist es aber nicht kompatibel.
Smartphone/Tablet: Egal ob Apple oder Android, dieses eBook können Sie lesen. Sie benötigen eine Adobe-ID sowie eine kostenlose App.
Geräteliste und zusätzliche Hinweise

Buying eBooks from abroad
For tax law reasons we can sell eBooks just within Germany and Switzerland. Regrettably we cannot fulfill eBook-orders from other countries.

EPUB (Adobe DRM)
Größe: 18,5 MB

Dateiformat: EPUB (Electronic Publication)
EPUB ist ein offener Standard für eBooks und eignet sich besonders zur Darstellung von Belletristik und Sachbüchern. Der Fließtext wird dynamisch an die Display- und Schriftgröße angepasst. Auch für mobile Lesegeräte ist EPUB daher gut geeignet.

Buying eBooks from abroad
For tax law reasons we can sell eBooks just within Germany and Switzerland. Regrettably we cannot fulfill eBook-orders from other countries.

Print-Ausgabe

Buch | Hardcover

119,70 €