Functional aspects

Many biological functions have been attributed to complex carbohydrates, but the subject is still mainly a matter of speculation. It is in this direction that future research will put increasing effort, based on the progress in isolation and characterization methods, as well as in biosynthetic studies. We shall refer to some of the postulated functions, together with supporting experimental evidence. 

Recognition systems in animal cells have been extensively reviewed. Some examples include the D-galactose- and L-fructose-recognition system of mammalian hepatocytes,233,234 the 2-acetamido-2-deoxy-D-glucose-recogni- 

Studies on the white clover -Rhizobium trifolii interaction are the most advanced. Trifoliin A, a lectin present in clover-seedling roots, binds hapten reversibly to carbohydrate antigens cross-reactive on the capsular polysaccharide of R. trifolii and clover epidermal-cells.244 A specific hapten that inhibits binding of trifoliin A to both surfaces is 2-deoxy-D-arabino-hexose.245 It has also been shown that levels of trifoliin A on root hairs decline with increasing concentrations of nitrate, in parallel to root-nodule development,246 and that lectin receptors are transient on R. trifolii, in a way coinciding with its capacity to be adsorbed to clover roots.247 

In Section III, it was mentioned that cell wall is a complex structure formed by different polysaccharides connected to glycoproteins. Hydroxy-L-proline-rich glycoproteins, such as extensin, have been found in almost all plants surveyed, and in some algae.203,281 A network of protein, pectic polymers, and xyloglucan, serving to cross-link the cellulose fibers of the cell wall, has been proposed.282,283 However, covalent links between the different components have not been demonstrated moreover, some of them can be extracted separately,284 and some associations may be artificial.285 Nevertheless, results are consistent with interactions through dipole-dipole (such as hydrogen bonds) or hydrophobic bonds. 

A fundamental role in cell extension has been proposed for hydroxy-L-proline-rich glycoproteins.286 Evidence for this involvement in cell extension 

A heuristic approach to analyzing the properties of residues directly involved in enzyme catalysis, using secondary structure, solvent accessibility, flexibility, conservation of quaternary structure, and function, was recently published by Bartlett et al. [42]. Such studies will help to provide a more general picture of the environment of enzyme active sites. 

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Computer System. The brain of the modern clinical chemistry analyzer is its computer system. The part of the computer system that controls the functional aspects of the analyzer is known as the process control computer or analytical processor (AP) the test results are handled by the data management computer, also known as the results processor (RP). 

RH Holm, P Kennepohl, El Solomon. Structural and functional aspects of metal sites in biology. Chem Rev 96 2239-2341, 1996. 

Acuna V, Munoz I, Giorgi A et al (2005) Drought and postdrought recovery cycles in an intermittent Mediterranean stream structural and functional aspects. J North Am Benthol Soc 24 919-933... 

These were relatively low-resolution structures, and with refinement some errors in the initial structural assignments have been detected (4-7). Since the structures were first reported the subject has been extensively reviewed in this series (8) and elsewhere 9-15). This review will focus on the structure, biosynthesis, and function of the met-allosulfur clusters found in nitrogenases. This will require a broader overview of some functional aspects, particularly the involvement of MgATP in the enzymic reaction, and also some reference will be made to the extensive literature (9, 15) on biomimetic chemistry that has helped to illuminate possible modes of nitrogenase function, although a detailed review of this chemistry will not be attempted here. This review cannot be fully comprehensive in the space available, but concentrates on recent advances and attempts to describe the current level of our understanding. 

Although controversial, findings as to how chronically administered morphine modulates neutrophil chemotaxis and function, a growing consensus believes that morphine is suppressive in the recruitment and functional aspects of these cells during an innate immune response. When peripheral human blood neutrophils were pretreated with exogenous opioids, lL-8-induced chemotaxis was inhibited (Grimm et al. 1998). Conversely, Simpkins et al. reported an increase in neutrophil chemotaxis... 

SANDERSON G w (1972) The chemistry of tea and tea manufacturing , in Runeckles V C, Structural and Functional Aspects of Phytochemistry, New York, USA, Academic Press, 247-316. 

Functional Aspects of Hydrocolloids in Controlling Crystal Structure in Foods... 

NASH—CONTROLLING CRYSTAL STRUCTURE IN FOODS FUNCTIONAL ASPECTS... 

Gartner, A., and Weser, U. Molecular and Functional Aspects of Superoxide Dismutases. 132, 1-61 (1986). 

Schnittler HJ. Structural and functional aspects of intercellular junctions in vascular endothelium. Basic Res Cardiol 1998 93 30-39. 

Breiteneder, H. and Mills, C.E.N., Plant food allergens — structural and functional aspects of allergenicity. Biotechnol. Ad., 23, 395, 2005. 

Bemasconi, R., Mathivet, P., Otten, U., Bettler, B., Bischoff, S., and Marescaux, C. (2002) Part of gamma-hydroxybutyrate pharmacological actions are mediated by GABAB receptors, in Gamma-Hydroxybutyrate Pharmacological and Functional Aspects (Tunnicliff, G. and Cash, C. D., eds), Taylor Francis, New York, pp. 28-63. 

Stuehr, D. J., Structure-function aspects in the nitric oxide synthases, Annu. Rev. Pharmacol. Toxicol. 37 (1997), p. 339-359... 

Sobti RC, Obe G. Eukaryotic Chromosomes Structural and Functional Aspects, Springer-Verlag, New York, 1991. 

Meldal, M., Christiansen-Brams, I., Christensen, M. K., Mouritsen, S., and Bock, K., in Complex Carbohydrates in Drug Research. Structural and Functional Aspects, Bock, K, and Clausen, H., (Eds.), Munksgaard, Copenhagen, 1994, pp. 153-165. 

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