Derek Marsh

Bio: Derek Marsh is an academic researcher from Max Planck Society. The author has contributed to research in topics: Spin label & Lipid bilayer. The author has an hindex of 73, co-authored 423 publications receiving 21001 citations. Previous affiliations of Derek Marsh include University of Southern Denmark.

Handbook of Lipid Bilayers, Second Edition

Abstract: INTRODUCTION Lipid Classification Nomenclature of Lipids Fatty Acids PHOSPHOLIPIDS Phospholipid Classification and Molecular Weights Fatty Acid Composition of Naturally Occurring Phospholipids and of Membrane Lipids from the Yeast Lipidome Physicochemical Properties of Phospholipids Phospholipid pKas Crystal Structures of Phospholipids Phase Behavior and Hydration Calorimetric Data X-Ray Diffraction Data Densitometric Data Elastic Constants Dynamic Properties Phase Transition Temperatures Phase Diagrams: Binary and Ternary Mixtures Non-Lamellar Phases (Hexagonal and Cubic) Critical Micelle Concentrations and Lipid Transfer Bilayer-Bilayer Interactions Ion-Binding Constants GLYCOLIPIDS Glycolipid Classification and Molecular Weights Fatty Acid Composition of Naturally Occurring Glycolipids Physicochemical Properties of Glycolipids Glycolipid pKas Crystal Structures Phase Behavior and Hydration Calorimetric Data X-Ray Diffraction Data Densitometric Data Elastic Constants Dynamic Properties Phase Transition Temperatures Phase Diagrams: Binary Mixtures Non-Lamellar Phases (Hexagonal and Cubic) Critical Micelle Concentrations and Lipid Transfer Bilayer-Bilayer Interactions Ion-Binding Constants.

Phospholipid Bilayers: Physical Principles and Models

Abstract: Bilayer Properties Self-Assembly Lipid Hydration Surface Electrostatics Hydrated Surfaces in Ionic Solutions Solute - Bilayer Interactions, Binding and Transport Interbilayer Forces, Aggregation and Fusion Bilayer Phase Transitions Chain Rotational Isomerism Bilayer Models Fluid Phase Elasticity Lateral Phase Separation Non-Bilayer Phases Index.

Structural characterization of copper(II) binding to α-synuclein: Insights into the bioinorganic chemistry of Parkinson's disease

Abstract: The aggregation of α-synuclein (AS) is characteristic of Parkinson's disease and other neurodegenerative synucleinopathies. We demonstrate here that Cu(II) ions are effective in accelerating AS aggregation at physiologically relevant concentrations without altering the resultant fibrillar structures. By using numerous spectroscopic techniques (absorption, CD, EPR, and NMR), we have located the primary binding for Cu(II) to a specific site in the N terminus, involving His-50 as the anchoring residue and other nitrogen/oxygen donor atoms in a square planar or distorted tetragonal geometry. The carboxylate-rich C terminus, originally thought to drive copper binding, is able to coordinate a second Cu(II) equivalent, albeit with a 300-fold reduced affinity. The NMR analysis of AS–Cu(II) complexes reveals the existence of conformational restrictions in the native state of the protein. The metallobiology of Cu(II) in Parkinson's disease is discussed by a comparative analysis with other Cu(II)-binding proteins involved in neurodegenerative disorders.

Membrane lipids: where they are and how they behave.

Abstract: Throughout the biological world, a 30 A hydrophobic film typically delimits the environments that serve as the margin between life and death for individual cells. Biochemical and biophysical findings have provided a detailed model of the composition and structure of membranes, which includes levels of dynamic organization both across the lipid bilayer (lipid asymmetry) and in the lateral dimension (lipid domains) of membranes. How do cells apply anabolic and catabolic enzymes, translocases and transporters, plus the intrinsic physical phase behaviour of lipids and their interactions with membrane proteins, to create the unique compositions and multiple functionalities of their individual membranes?

Lipid Rafts As a Membrane-Organizing Principle

Abstract: Cell membranes display a tremendous complexity of lipids and proteins designed to perform the functions cells require. To coordinate these functions, the membrane is able to laterally segregate its constituents. This capability is based on dynamic liquid-liquid immiscibility and underlies the raft concept of membrane subcompartmentalization. Lipid rafts are fluctuating nanoscale assemblies of sphingolipid, cholesterol, and proteins that can be stabilized to coalesce, forming platforms that function in membrane signaling and trafficking. Here we review the evidence for how this principle combines the potential for sphingolipid-cholesterol self-assembly with protein specificity to selectively focus membrane bioactivity.

Update of the CHARMM All-Atom Additive Force Field for Lipids: Validation on Six Lipid Types

Abstract: A significant modification to the additive all-atom CHARMM lipid force field (FF) is developed and applied to phospholipid bilayers with both choline and ethanolamine containing head groups and with both saturated and unsaturated aliphatic chains. Motivated by the current CHARMM lipid FF (C27 and C27r) systematically yielding values of the surface area per lipid that are smaller than experimental estimates and gel-like structures of bilayers well above the gel transition temperature, selected torsional, Lennard-Jones and partial atomic charge parameters were modified by targeting both quantum mechanical (QM) and experimental data. QM calculations ranging from high-level ab initio calculations on small molecules to semiempirical QM studies on a 1,2-dipalmitoyl-sn-phosphatidylcholine (DPPC) bilayer in combination with experimental thermodynamic data were used as target data for parameter optimization. These changes were tested with simulations of pure bilayers at high hydration of the following six lipids: ...

In Vivo Imaging of Quantum Dots Encapsulated in Phospholipid Micelles

Abstract: Fluorescent semiconductor nanocrystals (quantum dots) have the potential to revolutionize biological imaging, but their use has been limited by difficulties in obtaining nanocrystals that are biocompatible. To address this problem, we encapsulated individual nanocrystals in phospholipid block-copolymer micelles and demonstrated both in vitro and in vivo imaging. When conjugated to DNA, the nanocrystal-micelles acted as in vitro fluorescent probes to hybridize to specific complementary sequences. Moreover, when injected into Xenopus embryos, the nanocrystal-micelles were stable, nontoxic (<5 x 10(9) nanocrystals per cell), cell autonomous, and slow to photobleach. Nanocrystal fluorescence could be followed to the tadpole stage, allowing lineage-tracing experiments in embryogenesis.