Associated state

The complementation experiments in which the A domain of a class 111 E-II is used as the phosphoryl group donor to the B domain of a second E-II molecule with either the same or different sugar specificity, while both are fixed in a membrane matrix, raises some intriguing issues about the association state of these proteins and the kinetics of their interactions. Do E-IIs form stable homologous complexes in the membranes If so, is it necessary to postulate the formation of stable heterologous complexes to explain, for example, the phosphorylation of the B domain of E. coli 11° by the A domain of ll , or can the data be explained by assuming a... 

To determine the nature of the associated state, gel filtration high-performance liquid chromatography (HPLC) has been performed in a number of detergents with... 

E-IIs solubilized in detergent may exist in a self-associated state [41,44,45,49,50,52,54,101]. In the case of Il , dissociation led to a lower activity in the overall reaction indicating functional interaction between the subunits [52]. 

Integration of Eq. (1.2.15) permits calculation of the fraction of ions present in the associated state and thus the degree of association and the association constant... 

Thus, if mentioned above is to be taken into consideration that absorption band in the region of 330-340 nm reflects to a certain extent the degree of fullerene molecules association in solution, we can come to the conclusion that the less the PVP molecular mass and the less the fullerene contents is the more fullerene molecules are in low associated state. It is quite probable that the increase of the fullerene contents in the complex brings to the formation of adducts, where not single fullerene C60 molecules are bonded with PVP but their associates. It can be one of the reasons of the observed fact of the difference of UV-VIS spectra of C60/PVP complex with PVP of different molecular mass (up to spectra crossover, which is a singular evidence that these compounds are nonidentical). 

AAA nucleotidases share the common property of altering the conformation or association state of proteins, so it is not surprising that the RC has been shown to prevent aggregation of several denatured proteins including citrate synthase and ribonuclease A [59-61]. The chaperone activity of the RC may explain why the RC plays a role in transcription apparently in the absence of an attached 20S proteasome [62]. 

Fig. 1. Left part Qualitative MO diagram in the C2, geometry of the Li + CI2 system. Right part Associated state correlations diagram. Diabatic correlations are shown in broken lines.

Recently Bogolytsin and co-authors (62) found that the associations of sulfur dioxide and other inorganic sulfur derivatives interact with the aromatic nuclei of lignins, and strongly influence their reaction and redox behavior. This association effect also forms a selective pre-association state in the sulfonation reaction in wood pulping. It is evident that a wide range of similar association effects may be present, but they remain to be detected and studied. 

Tan 6 curves from dmta thermograms of blends based on combinations of HPL/PVA(> 0) are shown in Figure 5 (10). The tan 6 transition, which is another measure of Ts, is broadened by the presence of HPL component, and it increases above that of the parent polymers consistent with dsc data. This can again be explained with the presence of strong interactions between the amorphous components which coexist in a closely associated state. 

Parenthetically, we wish to note that the initial association state results obtained from viscometric technique were declared some time ago to be invalid as a result of undefined technical difficulties. Suffice it to mention that the author of this erroneous assessment (reference to my book CARBANI0NS,... 

Several studies have appeared (12,13,14) in which the propagation reactions involving styryllithium were examined in mixed solvent systems comprising benzene or toluene and ethers. The kinetics were examined under conditions where the ether concentration was held constant and the active center concentration varied. In most cases, the kinetic orders of the reactions were identical to those observed in the absence of the ether. Thus, in part, the conclusion was reached (13,14) that the ethers did not alter the dimeric association state of polystyryllithium. The ethers used were tetrahydrofuran, diphenyl ether, anisole, and the ortho and para isomers of ethylanisole. 

We have examined the influence of diphenyl ether and anisole on the association of the polystyryllithium and the 1,1-diphenyl-methyllithium active centers in benzene solution. The analytical tool used was the vacuum viscometry method (1 .2. 2. ) which utilizes concentrated solutions of polystyryllithium and the terminated polymer in the entanglement regime. Our results show that the presence of these ethers can alter the association states of the foregoing active centers. These findings parallel previous work (2) involving tetrahydrofuran. 

The procedures used for styrene and benzene purification are given elsewhere (15) as is the technique used to study the association states U The viscometric method relies on the fact... 

---