Cell wall galactomannans

The structures of the cell-wall D-mannans of several other yeasts have been investigated381 by use of this exo-a-D-mannanase. Five were degraded to the (l->6)-a-D-mannan chain. Those which contained jB-linked d-mannosyl units or a-D-galactosyl groups in the side chains were not significantly hydrolyzed. However, removal, by partial hydrolysis with acid, of the a-D-galactosyl units from five galactomannans, and of /3-linked D-mannosyl units from three other D-mannans, rendered these polysaccharides partially susceptible to hydrolysis by exo-a-D-mannanase, consistent with an a-linked-D-mannan structure. 

Dea, I. C. M., McKinnon, A. A., and Rees, D. A. (1972). Tertiary and quaternary structure in aqueous polysaccharide systems which model cell wall cohesion reversible changes in conformation and association of agarose, carrageenan and galactomannans. J. Mol. Biol. 68 153-172. 

The galactomannan from Schizosaccharomyces pombe cell-wall has a structure similar to that of S. octosporus.138 It is present in the outer layer, as shown by electron microscopy with the aid of an a-D-galacto-pyranosyl-binding lectin from Bandeiraea simplicifolia,139... 

In addition to chitin (O Sect. 2.2), yeast cell walls may contain a (1 3)- -glucan, a (1 6)- -glucan, various mannans, or a galactan. Other cell-wall components of certain fungi are rhamnomannans, glucomannans, galactomannans, xylomannans, glucuronoxylomannans, and other polysaccharides [42]. 

Gidley MJ, Reid JSG (2006) Galactomannans and other cell wall storage poysaccharides in seeds. In Reference 9, p 181... 

Cytoplasmic Peptidophosphogalactomannan. Fungal peptido-galactomannans have been extracted from powdered preparations (43). However, we were unable to obtain phosphogalactomannan from the cell walls of 3-day cultures of charlesii (20). When we examined extracts of P. charlesii cells we found galactofurano-syl residues both in a soluble cytoplasmic and a membrane-bound cytoplasmic fraction. 

Edwards, M.E. et ah, The seeds of Lotus japonicus fines transformed with sense, antisense, and sense/ antisense galactomannan galactosyltransferase constructs have structurally altered galactomannans in their endosperm cell walls, Plant Physiol, 134,1153, 2004. 

Gidley, M.J., Reid, J.S.G., 2006. Galactomannans and other cell wall storage polysaccharides in seeds. In Stephen, A.M., Phillips, G.O., Williams, P.A. (eds.) Food Polysaccharides and Their Applications, 2nd edn. Taylor Francis, Boca Raton, FL, pp. 181-215. 

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