amyloid precursor protein


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Related to amyloid precursor protein: amyloidosis, Tau protein

amyloid precursor protein

n. Abbr. APP
A protein found in cell membranes that forms beta-amyloid fragments when cleaved by the secretase designated beta.

amyloid precursor protein (APP)

a large transmembrane glycoprotein expressed on the cell surface and of uncertain function; it may be cleaved on the cell surface to a soluble form. Alternatively, cleavage may follow endocytosis and in some cases then yields 40 to 43 abnormal amino acid peptides, which aggregate to form Ab amyloid, associated with Alzheimer's disease.

amyloid precursor protein

Abbreviation: APP
An integral membrane protein concentrated at neuron synapses that is cleaved biochemically into components, one of which is the Alzheimer's disease–associated beta amyloid. Mutations in the gene for APP on chromosome 21 account for less than 5% of early-onset familial Alzheimer's disease.
See also: protein

amyloid precursor protein

A natural brain protein that is coded for on chromosome 21. This protein is related in some way to memory. Point mutations are found in the gene for this protein in people who suffer from a familial form of early-onset ALZHEIMER'S DISEASE. Only a small proportion of cases of Alzheimer's disease, however, are caused in this way. Abnormally folded AMYLOID protein in the form of plaques and tangles occur in brain cells in Alzheimer's disease but also in chronic suppurative states in other parts of the body.
References in periodicals archive ?
While it had been known that an abundance of iron in brain cells somehow results in an abundance of amyloid precursor protein, or APP, and its destructive peptide offspring, Rogers' team set out to open up new avenues for therapies by determining what goes on at the molecular level.
These plaques are predominantly composed of beta amyloid protein, which is derived from the proteolytic processing of amyloid precursor protein.
Some researchers have suspected that Alzheimer's results from an inherited or acquired genetic garble that causes cells to produce defective amyloid precursor protein.
This study is significant because it shows that DHA added to the diet altered the processing of the amyloid precursor protein and the accumulation of its toxic amyloid protein metabolite that is widely believed to cause Alzheimer's.
Beta amyloid, he notes, is actually a snippet of protein cleaved from a much larger protein called amyloid precursor protein (APP), which sticks out from cell membranes.
Preclinical studies have shown that it improves cognitive function, increases levels of acetylcholine (ACh), demonstrates synergy with acetylcholinesterase inhibitors, and may increase the neuroprotectants soluble amyloid precursor protein (sAPP) and brain-derived neurotrophic factor (BDNF) in regions of the brain known to be important for memory.
Jongens associate professor of Genetics at the University of Pennsylvania School of Medicine, worked with the familial form of Alzheimer's disease (FAD), an aggressive form of the disease that is caused by mutations in one of the two copies of the presenilin (PS) or amyloid precursor protein (APP) genes.
Prana Biotechnology Limited , today announced that the Journal of Biological Chemistry has published a new paper in its September 30 edition called "Clioquinol Mediates Copper Uptake and Counteracts Cu Efflux Activities of the Amyloid Precursor Protein of Alzheimer's Disease.
However, other experiments indicate that normal brain enzymes could easily cut her fragment from the amyloid precursor protein.
Spanish researchers coordinated by Doctors Maria Angeles Mena and Justo Garcia de Yebenes, from CIBERNED (Centro de Investigacion Biomedica en Red de Enfermedades Neurodegenerativas), found that anaesthesia is safe for normal mice but potentially harmful for mice with mutations of the amyloid precursor protein (APP).
Scientists at the Fisher Center and other research institutes had previously shown that beta-amyloid is produced when a large protein called APP, or amyloid precursor protein, is chopped into smaller pieces by scissor-like proteins called beta-secretase and gamma-secretase.
PRX-03140 is highly selective for the 5-HT4 receptor in the brain, and preclinical studies have shown that it improves cognitive function, as well as increases levels of acetylcholine (ACh), soluble amyloid precursor protein (sAPP) and brain-derived neurotrophic factor (BDNF) in regions of the brain known to be important for memory.