Cell wall amyloids

Sipe, J. D., Johns, M. A., Ghezzi, P., and Knapschaefer, G. Modulation of serum amyloid A gene expression by cytokines and bacterial cell wall components. Adv. Exp. Med. Biol. 243, 193-201 (1988). 

Glucomannans occur as reserve materials in certain seeds such as bluebell (Endymion non-scriptus) while the mucilages of other species are or contain polyuronides. Xyloglucans (with galactose side chains) are found as amyloids in seeds of tamarind Tamarindus) [65], Annona [43] and several other species. These polysaccharides again are deposited in the endosperm cell walls. 

Some of the /3-amyloid proteins are built from a double or triple strand helix called /3-helix, formed by the association of parallel /3 strands in a helical pattern. The structure was first found in the tail region of bacteriophages P22 and T4 where a rigid structure that would sustain the mechanical injection of DNA into bacterial cell body through cell wall and cell membrane [58, 59] and the growth property of amyloid protein was studied using TIRFM [60]. 

The hypothesis that the walls of suspension-cultured cells reflect the walls of intact plants is further substantiated by the fact the xyloglucan, a hemicellulosic component of the cell walls of bean and pea plants, is extremely similar to the xyloglucan of suspension-cultured sycamore cells (133). Indeed, amyloids, polysaccharides which can not be structurally... 

Xyloglucan is perhaps the most thoroughly understood of the non-cellulosic polysaccharides of primary cell walls 31). Xyloglucans were first characterized as an amyloid component of seeds 21, 60, 61, 79,... 

Considerably later, xyloglucans were isolated from the medium of suspension-cultured sycamore (24) cells, and, finally, from the primary cell walls of suspension-cultured sycamore cells (31). The basic structure of xyloglucans was elucidated by Kooiman (79) who studied the amyloid of Tamarindus indica seeds. The xyloglucans of primary cell walls were isolated and structurally characterized before it was recognized that the xyloglucans are very similar to the amyloids 31). The widespread occurrence of the amyloids 21, 67, 79, 115, 119) and xyloglucans 24, 29, 31) shows that polysaccharides isolated from tissues other than primary cell walls can, at times, serve as excellent models for the cell wall polysaccharides. 

Another prominent site of deposition of (5-amyloid fibrils with age and in AD is within the cerebrovasculature in areas of the brain prone to parenchymal amyloid deposition [137-139]. The peptide deposits along the surfaces of the smooth muscle cells of the vascular wall, resulting in the death of those cells and their replacement by amyloid fibrils, weakening the vascular wall. Endothelial cells are also affected [140]. The Dutch mutation in the APP precursor protein Q22E, within the (5-peptide sequence, produces a particularly fibrillogenic and toxic (to smooth muscle cells) peptide associated with primarily vascular deposition of mutant peptide and hemorrhagic vessel disease [137]. Thus, in addition to neuronal cells, the brain vascular smooth muscle cells are a pathologically relevant cell type. While the source of... 

Ascocarps lirelliform, not bordered by thallus. Receptacle often carbonized. Asci not amyloid. Spores two-celled, thin-walled, colorless to mostly colored, often verrucose, the cells not lens-shaped. Pycnospores long. Algae trentepohlioid. On various substrates. 

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