Christiane Unger

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Carrot (Daucus carota), like most other plants, contains various isoenzymes of acid beta-fructofuranosidase (beta F) (invertase), which either accumulate as soluble polypeptides in the vacuole (isoenzymes I and II) or are ionically bound to the cell wall (extracellular beta F). Using antibodies against isoenzyme I of carrot soluble beta F, we isolated(More)
Sucrose synthase (EC from carrot (Daucus carota) is a tetramer with a molecular mass of 320 kD and subunits of 80 kD. The enzyme has a pH optimum of 7.0 (cleavage direction). Maximal activities were measured at 55 degrees C. The Km for Suc was estimated as 87 mM and for UDP as 0.39 mM. Fructose acts as a noncompetitive inhibitor with an inhibition(More)
Soluble beta-fructofuranosidase with an intracellular location and an isoelectric point of 3.8 (isoenzyme I) was purified and characterized from dry seeds and seedlings of carrot (Daucus carota). The enzyme hydrolyzed sucrose with a Km of 5 mM and a broad pH optimum around 5.0. The purified protein, which was N-glycosylated with high-mannose-containing and(More)
Acetylcholinesterase (AChE) is shown to promote deposition of beta-amyloid (Abeta) peptides and to enhance Abeta toxicity. Tg2576 (transgenic mice carrying the Swedish mutation of amyloid precursor protein, APPswe) mice and mice overexpressing human synaptic acetylcholinesterase (AChE-S) were crossed (hAChE-Tg//APPswe), to study the effects of brain Abeta,(More)
Calcineurin is an abundant cytosolic protein that is implicated in the modulation of glutamate release. Here we show that the expression level of this enzyme is reduced in primary neuronal cultures treated with beta-amyloid. Parallel experiments in ETNA cell lines expressing SOD1 suggested that the effect of beta-amyloid on calcineurin expression is(More)
The mechanism for a large loss of neuronal nicotinic acetylcholine receptors (nAChRs) in brains with neurodegenerative diseases remains unclear. Based on our previous results of [(3)H]epibatidine binding influenced by lipid peroxidation, we suggest that nAChR deficit in neurodegenerative diseases might be related to the neurons attacked by free radicals. To(More)
The cerebral deposition of Abeta-peptide as amyloid fibrils and plaques represents a hallmark characteristic of Alzheimer's disease (AD). AD plaques are defined by their green birefringence after Congo red staining, their spherulite-like superstructure and their association with specific secondary components. Here we show that primary human macrophages(More)
Amyloid diseases are characterized by the formation of insoluble amyloid fibrils from previously soluble polypeptides. In Alzheimer's disease (AD), amyloid fibrils, formed from beta-amyloid peptides, are deposited as extracellular amyloid plaques only inside the brain. As previously shown, Alzheimer's-like plaque formation in human monocyte culture(More)
Quantitative and qualitative changes in protein methylation have been observed during the treatment of alfalfa cell cultures witl] fungal elicitor. Suspension cultures were treated with elicitor and fed with [~ in the presence of cycloheximide to inhibit protein synthesis. Several proteins were selectively methylated in response to elicitation and by 48hrs(More)
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