A new update of MALDI-TOF mass spectrometry in lipid research.

Matrix-assisted laser desorption and ionization (MALDI) mass spectrometry (MS) is an indispensable tool in modern lipid research since it is fast, sensitive, tolerates sample impurities and provides spectra without major analyte fragmentation. We will discuss some methodological aspects, the related ion-forming processes and the MALDI MS characteristics of the different lipid classes (with the focus on glycerophospholipids) and the progress, which was achieved during the last ten years. Particular attention will be given to quantitative aspects of MALDI MS since this is widely considered as the most serious drawback of the method.

Insights into structure, affinity, specificity, and function of GAG-protein interactions through the chemoenzymatic preparation of defined sulfated oligohyaluronans.

High amounts of glycosaminoglycans (GAG) such as hyaluronan (HA) occur in connective tissues. There is nowadays increasing evidence that a "sulfation code" exists which mediates numerous GAG functions. High molecular weight and inhomogeneity of GAG, however, aggravated detailed studies.

Characterization of defined sulfated heparin-like oligosaccharides by electrospray ionization ion trap mass spectrometry.

Glycosaminoglycans (GAG) as long, unbranched polysaccharides are major components of the extracellular matrix. Many studies provided additional evidence of a specific binding between mediators and sulfated GAG, at which the sulfation code-which means the number and positions of sulfate groups along the polysaccharide chain-plays an important role. GAG from natural sources are very inhomogeneous regarding their sulfation patterns and molecular weight.

Syntheses of defined sulfated oligohyaluronans reveal structural effects, diversity and thermodynamics of GAG-protein binding.

Binding of sulfated glycosaminoglycans (GAG) to a wide spectrum of extracellular regulatory proteins is crucial for physiological processes such as cell growth, migration, tissue homeostasis and repair. Thus, GAG derivatives exhibit great relevance in the development of innovative biomaterials for tissue regeneration therapies. We present a synthetic strategy for the preparation of libraries of defined sulfated oligohyaluronans as model GAG systematically varied in length, sulfation pattern and anomeric substitution in order to elucidate the effects of these parameters on GAG recognition by regulatory proteins.

N-terminal lipid conjugation of amyloid β(1-40) leads to the formation of highly ordered N-terminally extended fibrils.

Fibril formation of amyloid β(1-40) (Aβ(1-40)) peptides N-terminally lipid modified with saturated octanoyl or palmitoyl lipid chains was investigated. Lipid modification of Aβ(1-40) significantly accelerates the fibrillation kinetics of the Aβ peptides as revealed by ThT fluorescence. Electron microscopy and X-ray diffraction results indicate a heterogeneous cross-β structure of the fibrils formed by the lipid-conjugated peptides.

Chemoenzymatic Synthesis of Nonasulfated Tetrahyaluronan with a Paramagnetic Tag for Studying Its Complex with Interleukin-10.

Implants and artificial biomaterials containing sulfated hyaluronans have been shown to improve the healing of injured skin and bones. It is hypothesized that these effects are mediated by the binding of sulfated glycosaminoglycans (GAGs) to growth factors and cytokines, resulting in the sequestering of proteins to the wound healing site and in modulated protein activity. Given that no direct synthetic access to sulfated oligohyaluronans has been available, little is known about their protein binding and the structure of the resulting protein complexes.

Regioselective Ring-Opening Polymerization of a Polyhydroxycarboxylic Acid for the Synthesis of a Nanoscale Carrier Material with pH-Dependent Stability and Sustained Drug Release.

Synthetic polyesters are usually composed of monohydroxycarboxylic acids to avoid the problem of regioselectivity during ring-opening polymerization. In contrast, the linear polyester BICpoly contains four secondary OH groups and is nevertheless esterified regioselectively at only one of these positions. Neither the synthesis of the tricyclic monomers nor the ring-opening polymerization requires protecting groups, making BICpoly an attractive novel and biocompatible polymer.

Structural analysis of the interleukin-8/glycosaminoglycan interactions by amide hydrogen/deuterium exchange mass spectrometry.

The recruitment of different chemokines and growth factors by glycosaminoglycans (GAGs) such as chondroitin sulfate or hyaluronan plays a critical role in wound healing processes. Thus, there is a special interest in the design of artificial extracellular matrices with improved properties concerning GAG interaction with common regulating proteins. In this study, amide hydrogen/deuterium (H/D) exchange mass spectrometry (HDX MS) combined with molecular modeling and docking experiments was used to obtain structural models of proinflammatory chemokine interleukin-8 (IL-8) in complex with hexameric chondroitin sulfate.

Improvement of the digestibility of sulfated hyaluronans by bovine testicular hyaluronidase: a UV spectroscopic and mass spectrometric study.

Glycosaminoglycans (GAGs) such as hyaluronan (HA) and chondroitin sulfate (CS) are important, natural polysaccharides which occur in biological (connective) tissues and have various biotechnological and medical applications. Additionally, there is increasing evidence that chemically (over)sulfated GAGs possess promising properties and are useful as implant coatings. Unfortunately, a detailed characterization of these GAGs is challenging: although mass spectrometry (MS) is one of the most powerful tools to elucidate the structures of (poly)saccharides, MS is not applicable to high mass polysaccharides, but characteristic oligosaccharides are needed.