Amyloid-associated protein

Ma J, Brewer HB Jr, Das S, Potter H. 1994. Amyloid-associated proteins al-phal-antichymotrypsin and apolipoprotein E promote assembly of Alzheimer beta-protein into filaments. Nature 372 92-94... 

Alzheimer s disease in which the pathogenicity of amyloid peptides depends on proteases, namely secretases, involved in amyloid precursor protein (APP) maturation. This chapter will describe how the proteolysis of chemokines might participate in the neuropathogenesis of HIV infection, thus contributing to the development of the central nervous system disorder termed HIV-associated dementia (HAD). 

Several pathological self-polymerizing systems have been biophysi-cally characterized sufficiently to permit identification of protein or peptide species that could serve as molecular targets in a structure-activity relationship. These include transthyretin (TTR) [73-76], serum amyloid A protein (SAA) [77], microtubule-associated protein tau [78-80], amylin or islet amyloid polypeptide (IAPP) [81,82], IgG light chain amyloidosis (AL) [83-85], polyglutamine diseases [9,86], a-synuclein [47,48] and the Alzheimer s (3 peptide [87-96]. A variety of A(3 peptide assay systems have been established at Parke-Davis to search for inhibitors of fibril formation that could be therapeutically useful [97]. 

The failure of proteins to fold into their functional forms can occasionally lead to "misfolding" or "conformational" diseases.140 Many of these diseases are associated with the formation of amyloid protein, an insoluble material that is deposited as fibrils or plaques in different tissues and organs of the body. They include amyloid Ap protein as the major constituent of the plaques in Alzheimer patients, PrPc associated with neuro-degenerative diseases, a-synuclein (AS) associated with Parkinson s diseases, transthyretin (TTR) as a homotetrameric protein that is involved in the transport of thyroid hormones and retinol in human serum. In particular, the Ap protein is a peptide of 39-43 amino acids that is the... 

Lashuel, H. A., Petre, B. M., Wall, J., Simon, M., Nowak, R. J., Walz, T., and Lansbury, P. T., Jr. (2002). Alpha-synuclein, especially the Parkinson s disease-associated mutants, forms pore-like annular and tubular protofibrils./. Mol. Biol. 322,1089-1102. LeVine, H. (1993). Thioflavine T interaction with synthetic Alzheimer s disease beta-amyloid peptides Detection of amyloid aggregation in solution. Protein Sci. 2, 404—410. Lin, H., Bhatia, R., and Lai, R. (2001). Amyloid beta protein forms ion channels Implications for Alzheimer s disease pathophysiology. FASEB J. 15, 2433-2444. Lorenzo, A., and Yankner, B. A. (1994). Beta-amyloid neurotoxicity requires fibril formation and is inhibited by Congo red. Proc. Natl. Acad. Sci. USA 91, 12243-12247. Luhrs, T., Ritter, C., Adrian, M., Riek-Loher, D., Bohrmann, B., Dobeli, H., Schubert, D., and Riek, R. (2005). 3D structure of Alzheimer s amyl o id-( be la) (1—12) fibrils. Proc. Natl. Acad. Sci. USA 102, 17342-17347. 

Murrell, J., Farlow, M., Ghetti, B., Benson, M.D. (1991) A mutation in the amyloid precursor protein associated with hereditary Alzheimer s disease. Science, 254,97-99. 

Nicoll, J.A.R., Roberts, G.W., Graham, D.l. (1995) ApoUpoprotein E epsUon-4 allele is associated with deposition of amyloid beta-protein foUowing head injury. Nat. Med., 1, 135-137. 

Mann, D.M., Iwatsubo, T., Pickering-Brown, S.M., Owen, F., Saido, T.C., Perry, R.H. (1997) Preferential deposition of amyloid beta protein (Abeta) in the form of Abeta40 in Alzheimer s disease associated with a gene dosage effect of the apolipoprotein E E4 aUele. Neurosci. Lett., 221, 81-84. 

Patil SP, Maki S, Khedkar S A, Rigby AC, Chan C. (2010) Withanohde A and asiatic acid modulate multiple targets associated with amyloid-P precursor protein processing and amyloid-p protein clearance. J Nat Prod 73 1196-1202. 

C. It is associated with the accumulation of amyloid precursor protein. 

Microfibril-associated protein-1 (MFAP-1 also known as AMP), MFAP-3, and MFAP-4 (also known as MAGP-36) colocalize with microfibrils and elastic fibers in skin and other tissues (Abrams et al, 1995 Hirano et al, 2002 Horrigan et al., 1992 Lausen et al, 1999 Liu et al, 1997 Toyoshima et al, 1999). In aging and immune conditions, microfibrils can associate with amyloid deposits and accumulate a coating of adhesive glycoproteins, such as vitronectin (Dahlback et al, 1990). 

The microtubule-associated-protein tau is a component of the neurofibrillary tangles in Alzheimer s disease and a target of S100A1. PC 12 cells devoid of S100A1 were shown to be more resistant to A(3(25-35) peptide-mediated cell death and have lower levels of intracellular amyloid precursor protein (APP) (Zimmer et al., 2005). 

Figure 11.1 The amyloid hypothesis in Alzheimer s disease. The transmembrane protein amyloid precursor protein (APP) is cleaved first by f> -secretase (BACE), then by y -secretase. The resulting peptidic fragment, AfSAO/42, is liberated, leading to plaque accumulation. These plaques are associated with neuronal degeneration.

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