SiaNAl can be efficiently incorporated in glycoproteins of human mesenchymal stromal cells by metabolic glycoengineering.

Metabolic glycoengineering involves the stimulation of cells with functionalized monosaccharides. Glucosamine, galactosamine, and mannosamine derivatives are commercially available, but their application may lead to undirected (i.e.

Metabolic Glycoengineering in hMSC-TERT as a Model for Skeletal Precursors by Using Modified Azide/Alkyne Monosaccharides.

Metabolic glycoengineering enables a directed modification of cell surfaces by introducing target molecules to surface proteins displaying new features. Biochemical pathways involving glycans differ in dependence on the cell type; therefore, this technique should be tailored for the best results. We characterized metabolic glycoengineering in telomerase-immortalized human mesenchymal stromal cells (hMSC-TERT) as a model for primary hMSC, to investigate its applicability in TERT-modified cell lines.

Impaired Neurofilament Integrity and Neuronal Morphology in Different Models of Focal Cerebral Ischemia and Human Stroke Tissue.

As part of the neuronal cytoskeleton, neurofilaments are involved in maintaining cellular integrity. In the setting of ischemic stroke, the affection of the neurofilament network is considered to mediate the transition towards long-lasting tissue damage. Although peripheral levels of distinct neurofilament subunits are shown to correlate with the clinically observed severity of cerebral ischemia, neurofilaments have so far not been considered for neuroprotective approaches.

Damaged Neocortical Perineuronal Nets Due to Experimental Focal Cerebral Ischemia in Mice, Rats and Sheep.

As part of the extracellular matrix (ECM), perineuronal nets (PNs) are polyanionic, chondroitin sulfate proteoglycan (CSPG)-rich coatings of certain neurons, known to be affected in various neural diseases. Although these structures are considered as important parts of the neurovascular unit (NVU), their role during evolution of acute ischemic stroke and subsequent tissue damage is poorly understood and only a few preclinical studies analyzed PNs after acute ischemic stroke. By employing three models of experimental focal cerebral ischemia, this study was focused on histopathological alterations of PNs and concomitant vascular, glial and neuronal changes according to the NVU concept.

Mechano-optical octave-tunable elastic colloidal crystals made from core-shell polymer beads with self-assembly techniques.

Elastic colloidal crystals, even without a full photonic band gap, hold promise for fascinating applications and for easy large-scale fabrication by self-assembly. However, high mechanical robustness is required for optical, decorative, or security applications, such as tunable optical modulators/filters or optical tension indicators. Here, we present brilliantly colored filled-pore colloidal crystals that withstand elongation by 100%, i.

Three-dimensional bead position histograms reveal single-molecule nanomechanics.

We describe a method to investigate the structure and elasticity of macromolecules by a combination of single molecule experiments and kinematic modeling. With a photonic force microscope, we recorded spatial position histograms of a fluctuating microsphere tethered to full-length myosin-II. Assuming only that the molecule consists of concatenated rigid segments, a model derived from robot kinematics allows us to relate these histograms to the molecule's segment lengths and bending stiffnesses.

Mechanical properties of single myosin molecules probed with the photonic force microscope.

To characterize elastic properties and geometrical parameters of individual, whole myosin molecules during their interaction with actin we sparsely adsorbed myosin molecules to nanometer-sized microspheres. Thermally driven position fluctuations of these microspheres were recorded with the three-dimensional detection scheme of the photonic force microscope. Upon binding of single myosin molecules to immobilized actin filaments in the absence of ATP, these thermally driven position fluctuations of the microspheres change significantly.

Nucleotide-induced conformations in the neck region of dimeric kinesin.

The neck region of kinesin constitutes a key component in the enzyme's walking mechanism. Here we applied cryoelectron microscopy and image reconstruction to investigate the location of the kinesin neck in dimeric and monomeric constructs complexed to microtubules. To this end we enhanced the visibility of this region by engineering an SH3 domain into the transition between neck linker and neck coiled coil.

Pathways and intermediates in forced unfolding of spectrin repeats.

Spectrin repeats are triple-helical coiled-coil domains found in many proteins that are regularly subjected to mechanical stress. We used atomic force microscopy technique and steered molecular dynamics simulations to study the behavior of a wild-type spectrin repeat and two mutants. The experiments indicate that spectrin repeats can form stable unfolding intermediates when subjected to external forces.