amyloid-beta peptide

Examples of amyloid-beta peptide in the following topics:

• Alzheimer's Disease

  • In 1991, the amyloid hypothesis postulated that amyloid beta (Aβ) deposits are the fundamental cause of the disease.
  • In 2009, this theory was updated, suggesting that a close relative of the beta-amyloid protein, and not necessarily the beta-amyloid itself, may be a major culprit in the disease.
  • N-APP, a fragment of APP from the peptide's N-terminus, is adjacent to beta-amyloid and is cleaved from APP by one of the same enzymes.
  • In this model, beta-amyloid plays a complementary role, by depressing synaptic function.
  • Enzymes act on the APP (Amyloid precursor protein) and cut it into fragments of protein, one of which is called beta-amyloid and its crucial in the formation of senile plaques in AD

• Insulin Secretion and Regulation of Glucagon

  • Glucagon is a peptide hormone that works in conjunction with insulin to maintain a stable blood glucose level.
  • Glucagon and insulin are peptide hormones secreted by the pancreas that play a key role in maintaining a stable blood glucose level.
  • Insulin is produced by beta cells in the pancreas and acts to oppose the functions of glucagon.

• Digestive Processes of the Small Intestine

  • Proteins are degraded into small peptides and amino acids before absorption.
  • Proteolytic enzymes, including trypsin and chymotrypsin, are secreted by the pancreas and cleave proteins into smaller peptides.
  • This is because the cellulose is made out of beta-glucose that makes the inter-monosaccharidal bindings different from the ones present in starch, which consists of alpha-glucose.
  • Humans lack the enzyme for splitting the beta-glucose-bonds—that is reserved for herbivores and bacteria in the large intestine.

• Interactions of Hormones at Target Cells

  • Bundles of cells in the pancreas, called the islets of Langerhans, contain two kinds of cells: alpha cells and beta cells.
  • Beta cells secrete insulin.
  • When the concentration of blood glucose rises, such as after eating, beta cells secrete insulin into the blood.
  • Glucagon is a pancreatic peptide hormone that, as a counter-regulatory hormone for insulin, stimulates glucose release by the liver and maintains glucose homeostasis.

• Cerebrospinal Fluid and Its Circulation

  • The three biomarkers are CSF amyloid beta 1-42, total CSF tau protein, and P-Tau181P.

• Aging and the Endocrine System

  • Specifically, the protein beta-amyloid (Ab) collects in vulnerable brain regions and plays a central role in the progression of AD.

• Parasympathetic Responses

  • The parasympathetic nervous system uses chiefly acetylcholine (ACh) as its neurotransmitter, although peptides (such as cholecystokinin) may act on the PSNS as neurotransmitters.
  • Two different subtypes of nicotinic acetylcholine receptors with alpha and beta subunits are shown.

• Absorption of Monosaccharides, Amino Acids, Dipeptides, Tripeptides, Lipids, Electrolytes, Vitamins, and Water

  • Proteins are degraded into small peptides and amino acids before absorption.
  • Proteolytic enzymes, including trypsin and chymotrypsin, are secreted by the pancreas and cleave proteins into smaller peptides.
  • This is because the cellulose is made out of beta-glucose, making the inter-monosaccharidal bindings different from the ones present in starch, which consists of alpha-glucose.
  • Humans lack the enzyme for splitting the beta-glucose-bonds, something reserved for herbivores and bacteria from the large intestine.

• The Anterior Pituitary

  • Its regulatory functions are achieved through the secretion of various peptide hormones that act on target organs including the adrenal gland, liver, bone, thyroid gland, and gonads.
  • Beta-endorphin is a polypeptide that effects the opioid receptor, whose effects include the inhibition of the perception of pain.