Jürgen Kopitz

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Membrane glycoconjugates play a central role in neuronal interactions and regulation. To define the precise links between membrane polysaccharides and neuronal functions, two main requirements must be fulfilled: (1) the availability of molecular tools able to finely discriminate among carbohydrate structures and (2) the use of an experimental system(More)
The pathogenesis of age-related macular degeneration involves chronic oxidative stress, impaired degradation of membranous discs shed from photoreceptor outer segments and accumulation of lysosomal lipofuscin in retinal pigment epithelial (RPE) cells. It has been estimated that a major part of cellular proteolysis occurs in proteasomes, but the importance(More)
Age-related macular degeneration (AMD) is the major diagnosis for severe and irreversible central loss of vision in elderly people in the developed countries. The loss of vision involves primarily a progressive degeneration and cell death of postmitotic retinal pigment epithelial cells (RPE), which secondarily evokes adverse effects on photoreceptor cells.(More)
Orchestrated upregulation of cell surface presentation of ganglioside GM1 and homodimeric galectin-1 is the molecular basis for growth regulation of human neuroblastoma (SK-N-MC) cells. Further study led to the discovery of competitive inhibition by galectin-3, prompting us to test tandem-repeat-type galectin-4 (two different lectin domains connected by a(More)
PURPOSE Aging of the RPE is associated with a decrease of intracellular ATP levels and increased oxidative stress. We investigated the effects of moderate energy deficit on intracellular glutathione levels, oxidative damage of cellular proteins and DNA, and autophagy rates using an RPE cell culture model. Additionally, phagocytosis of photoreceptor outer(More)
Carbohydrates establish the third alphabet of life. As part of cellular glycoconjugates, the glycans generate a multitude of signals in a minimum of space. The presence of distinct glycotopes and the glycome diversity are mapped by sugar receptors (antibodies and lectins). Endogenous (tissue) lectins can read the sugar-encoded information and translate it(More)
Glycolipids are glycoconjugates that are predominantly found on the extracellular surface of cells ranging from bacteria to men. In bacteria and plants, glycoglycerolipids represent the main glycolipid species. Ceramides as carrier for glycans, termed glycosphingolipids (GSLs), are characteristic for vertebrates and insects. The glycan part is involved in a(More)
The cholinergic neurotransmitter system and prolonged glucocorticoid-induced stress can affect cognitive functions in opposite ways. While pharmacological enhancement of cholinergic neurotransmission is known to induce neuroprotective effects, chronic glucocorticoids impair cognitive functions. Up to now, there is no consensus as to whether a subchronic(More)
Mapping of proteins involved in normal eye functions is a prerequisite to identify pathological changes during eye disease processes. We therefore analysed the proteome of human vitreous by applying in-depth proteomic screening technologies. For ethical reasons human vitreous samples were obtained by vitrectomy from “surrogate normal patients” with(More)