Effects of Chemical Modification

Quadruplex formation is not restricted to DNA. A number of different oligomers with an altered sugar phosphate backbone are able to form G-quadruplexes.  

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Choi, S.-G. and Kerr, W.L. 2003b. Effect of chemical modification of wheat starch on molecular mobility as studied by pulsed H-1 NMR. Lebensm. If/vv. Technol. Food Sci. Technol. 36, 105-112. 

In 1979, Ross et al 22i" measured the ODMR of tyrosine in glucagon and the derivative [12-homoarginine]glucagon to examine the effect of chemical modification of a lysine residue adjacent to Tyr-10 and Tyr-13. The guanidinated analogue had lower potency than glucagon in a fat cell hormone receptor assay. Since the tyrosine ODMR and other spectral properties of the polypeptide, including circular dichroism, were essentially identical, it was... 

Table 4.1 The effect of chemical modification on water contact angles...

Mahlberg, R., Paajanen, L., Nurmi, A., Kivisto, A., Koskela, K. and Rowell, R.M. (2001). Effect of chemical modification of wood on the mechanical and adhesion properties of wood fiber/polypropylene fiber and polypropylene/veneer composites. Holz als Roh- und Werkstoff, 59(5), 319-326. 

Tandy, P., Fares, K., Lorient, D., and Voilley, A. Effect of chemical modification of sodium caseinate on diffusivity of aroma compounds in aqueous solutions, / Agric. Food Chem., 45(7) 2649-2653, 1997. 

Masuda, T., Ide, N. and Kitabake, N. 2005. Effects of chemical modification of lysine residues on the sweetness of lysozyme. Chemical Senses, 30 253-264. 

Wolf, W. B., Bauer, L. L., Fahey, G. C. Jr. (1999). Effects of chemical modification in vitro rate and extent of food starch digestion An attempt to discover a slowly digested starch. J. FoodAgric. Chem., 47, 4178 183. 

These results indicate that differences exist between the H2O2-bleaching chemistry depending on pH and that difference-FTIR spectroscopy is a useful method for revealing the effect of chemical modification on chemical structure. 

We have studied the effect of chemical modification on adsorption properties of natural clinoptilolite (18). Studies of water vapor adsorption show a decrease in adsorption for Dzegvi clinoptilolite, decationized and dealuminized on the water bath, with increased acid concentration, compared with the adsorption of the natural clinoptilolite. The main contribution to adsorption is from primary porosity. 

Effect of Chemical Modification with Polyethylene Glycol on the Brightness Stability of Lignin Model Compounds and High-Yield Pulp... 

In the remainder of this paper we review the available information on the effects of chemical modification on the functional properties of plant proteins and report on the use of this approach for preparing functional proteins from yeast. 

B. Effect of Carbamylation on Enzyme Binding. Figure 1. shows the effectiveness of chemical modification (cambamylation) in reducing the enzyme binding activity of membraneous collagen, where the quantity of enzyme sorbed is plotted as a function of... 

Figure 1. The effect of chemical modification of lysyl E-amino groups on the sorption of fi-galacatosidase (23 pmol/L) to collagen membrane. Solution equilibrium and steady-state reactor conditions.

B. Effect of Chemical Modification on Cell Wall Moisture Content... 

There are so many variables to consider in wood composites that is it also difficult to draw conclusions on the effect of chemical modification on mechanical properties of composites. The size, geometry, and orientation of... 

The ACE and ASE values obtained by the various modifications are compared in Fig. 3. The effect of chemical modifications on creep of wood has been characterized by ACE, analogous to ASE that quantifies the ability of the treatment to reduce load-free moisture expansion. Modification of the cell wall at the molecular level is required to affect either moisture expansion or creep. Depending on the type of treatment, this can be obtained through... 

This section is concerned primarily with the effects of chemical modifications of keratins on their physical properties—supercontraction, setting, swelling, load-extension characteristics, and other mechanical properties. Much of this work could be described by the term mechanochemical coined by Speakman (1947). The complexity of the cellular and sub-cellular structure of keratins necessitates the use of simplifying assumptions in the interpretation of mechanochemical experiments. 

The cystine residues, because they may act as cross-linkages between protein chains, have been studied more closely than other residues in keratin. Burley s (1956a) use of the concept of thiol-disulfide interchange to explain the effects of chemical modification on the physical properties of wool fibers has stimulated further work on cysteine and cystine residues. 

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