A NOVEL AMYLOID COMPONENT

淀粉样蛋白作为衰老斑块的核心和沿着血管壁堆积。 在阿尔茨海默病(AD)患者的脑组织中。 淀粉样蛋白的主要成分是一种39-43个氨基酸的多肽，称为 淀粉样β蛋白/A4-蛋白(A/Beta)起源于约 10万道尔顿。最近的免疫学研究证明了许多 急性期蛋白与淀粉样蛋白相关，增加了 这种淀粉样蛋白可能由不止一种蛋白质组成。 然而，在生物化学方面，Abeta仍然是唯一已确定的成分。 多年来。然而，最近我们发现了一个新的组件 在AD淀粉样蛋白中的生物化学，并建议使用 分子生物学、生化、免疫学和细胞生物学 技巧。 70%甲酸增溶的纯化AD淀粉样蛋白的完全消化 酸，并用溴化氰和裂解无色杆菌酶消化 除了ABeta片段，我还得到了两个未知的多肽 序列。这些序列用于制备抗血清。两种抗血清 这些序列的一部分用来产生寡核苷酸，这些寡核苷酸 被聚合酶链式反应用来从脑基因文库中扩增DNA片段。一架247- 扩增出核苷酸DNA片段。这段短DNA的测序 证明了这种DNA编码了一种蛋白质，它包含一个完美的 与发现的淀粉样蛋白多肽序列相匹配。一种新的全长编码基因 含有两个新的淀粉样蛋白序列的蛋白质用 该聚合酶链式反应扩增了探针。我们称含有这些多肽的蛋白质为 NACP用于进一步的免疫组织化学和免疫化学分析 蛋白。将使用反义策略来鉴定生物 NACP的功能。最后，NAC或NACP和NAC之间的潜在相互作用 将对APP或Abeta进行调查。NAC和NACP的表征 应进一步阐明AD中淀粉样蛋白的发生，并可能有助于 寻找这种毁灭性疾病的病原学。

Amyloid accumulates as a core of senile plaques and along the vessel wall in the brain tissue of patients afflicted with Alzheimer's disease (AD). The major constituent of amyloid is a 39-43 amino acid peptide called amyloid Beta/A4-protein (A/Beta) derived from a precursor of around 100,000 daltons. Recent immunological studies have demonstrated many acute phase proteins are associated with amyloid, raising the possibility that amyloid might be composed of more than one type of protein. However, biochemically, Abeta had remained the only component identified for many years. However, recently, we have identified a new component in an AD amyloid biochemically and propose to study this protein using molecular biological, biochemical, immunological, and cell biological techniques. The complete digestion of purified AD amyloid, solubilized in 70% formic acid, and digested by cyanogen bromide and Achromobacter lyticus protease I yielded, in addition to ABeta fragments, two peptides of unknown sequence. These sequences were used to raise antisera. Two antisera portion of these sequences was used to generate oligonucleotide that were used by PCR to amplify DNA fragments from a brain cDNA library. A 247- nucleotide DNA segment was amplified. The sequencing of this short DNA demonstrated that this DNA encodes a protein that contains a perfect match with the peptide sequence found n amyloid. A full-length cDNA for the protein containing both two new amyloid sequence was isolated using this PCR amplified probe. We call the protein containing these peptide NACP for further immunohistochemical and immunochemical analysis of this protein. Antisense strategy will be used to identify the biological function of NACP. Finally, potential interaction between NAC or NACP and APP or Abeta will be investigated. Characterization of NAC and NACP should shed further light on the amyloidogenesis in AD and might help in finding the etiology of this devastating disease.