Amyloid fibrils in human insulinoma and islets of Langerhans of the diabetic cat are derived from a neuropeptide-like protein also present in normal islet cells.
AUTOR(ES)
Westermark, P
RESUMO
Amyloid deposits localized to the islets of Langerhans are typical of non-insulin-dependent human diabetes mellitus and of diabetes mellitus in adult cats. Amyloid deposits also commonly occur in insulin-producing pancreatic tumors. We have purified a major protein--insulinoma or islet amyloid polypeptide (IAPP)--from human and cat islet amyloid and from amyloid of a human insulinoma. IAPP from human insulinoma contained 37 amino acid residues and had a theoretical molecular mass of 3850 Da. The amino acid sequence is unique but has greater than 40% identity with the human calcitonin gene-related peptide. A partial amino acid sequence of cat islet IAPP corresponding to positions 1-27 of human insulinoma IAPP was identical to the human IAPP except for substitutions in three positions. An antiserum raised to a synthetic human insulinoma IAPP-(7-17) undecapeptide showed specific immunohistochemical reactivity with human and cat islet amyloid and with islet B cells. The significance of this pancreatic neuropeptide-like protein is unknown, but it is suggested that it may exert an important endocrine regulatory effect.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=304980Documentos Relacionados
- Identification of neuropeptide-like protein gene families in Caenorhabditis elegans and other species
- Transferrin receptors in rat brain: neuropeptide-like pattern and relationship to iron distribution.
- Intra- and extracellular amyloid fibrils are formed in cultured pancreatic islets of transgenic mice expressing human islet amyloid polypeptide.
- Acceleration of amyloid protein A amyloidosis by amyloid-like synthetic fibrils
- Amyloid. 3. A protein related to the subunit structure of human amyloid fibrils.