Conformation changes with

The unusual properties of xanthan undoubtedly result from its stmctural rigidity, which in turn is a consequence of its Linear, ceUulosic backbone that is stiffened and shielded by the trisaccharide side chains. The conformation of xanthan in solution is a matter of debate. It does appear that the conformation changes with conditions. 

Recently Rabon et al. [100] reported on a new conformational probe of H,K-ATPase. This fluorescent quinoline derivative MDPQ was shown to be a reversible luminal K -site inhibitor of both K -ATPase and K -pNPPase activity. High-affinity MgATP binding induced a conformational change with fluorophore movement into a more hydrophobic environment. 

In concluding this section, we wish to emphasize that extreme care is necessary when predicting the basicity of donor molecules from experimental or theoretical studies performed on these molecules in their free state. Such an approach appears to be correct when the acceptor moiety is H+ but may lead to error as the Lewis adduct becomes bulkier, since its volume induces dramatic conformational changes with... 

Rapid Characterization of Protein Conformational Change with DXMS 385. . ... 

Fluorescence spectroscopy S Conformational change with ligand binding induces change in fluorescence properties of intrinsic or extrinsic fluorophore... 

The relative population of chiral conformers changes with temperature. 

As I described in our excimer experiments, the polymer shows much flexibility. For allosteric effects it is not essential to have subunit systems. Thus the simple polymer macromolecule has the intrinsic ability to undergo conformational changes with accompanying changes in activity. But this too is an area in which we have made no experiments. In all experiments the kinetics has been Michaelian, with no evidence of interaction between sites. 

The stress-optical coefficient of PE networks is calculated, and results are compared with experimental data. Observed temperature coefficients of AT and the optical anisotropy for unswollen samples are much larger than those calculated using acceptable values of E(g), the energy of the gauche conformation, relative to that of Vans. It is concluded that observed temperature coefficients should Include some contributions other than those implied in the theory, i.e., those arising from the conformational change with temperature. 

It follows that the nascent b networks are best fitted for defining a reference state, because at the swelling ratio Qe the elastic chains are supposed to have undergone the smallest conformational changes with respect to the free chains they were before crosslinking. 

Type I (uninhibited) crystals. In a rather marked contrast, Fig. 6b shows the same view of the 4-A electron density map of the Type II (inhibited) crystals. A mass of electron density now appears in the pocket, and there also appears to be some added density at the left side of the perimeter of the pocket itself. It should perhaps be reemphasized here that these structures of the Type I and Type II crystals were determined completely independently using one set of heavy atoms and unsubstituted data for the uninhibited nuclease and another entirely different combination for the nuclease-inhibitor complex. However, the fact that heavy-atom positions appear very distinctly when intensities from Type I crystals are combined with Type II phases (and vice versa) indicates that the nuclease undergoes no gross conformational changes with pdTp and Ca2+ binding (31) thus, the kind of comparison presented... 

Initial binding of all substrates is followed by an isomerization or conformational change with a characteristic time constant of the order of magnitude of 103 sec-1. 

Lipid-free (Na+, K+)-ATPase is incapable of hydrolyzing ATP or p-nitrophenyl phosphate. The precise role of the lipid and the specificity for the lipid have not yet been determined. The addition of lipid to the delipidated enzyme brings about conformational changes, with phosphatase activity regenerated before ATPase activity.51 It seems evident that the lipid will affect the conformation of the enzyme and determine membrane fluidity, which is relevant to conformational change. 

In the plastic flow process, large displacements of the whole chain are performed to reach the involved strain values. Such displacements are analogous to those that happen during polymer flow above the glass-rubber transition (a transition) temperature. These motions are performed by segmental backbone conformation changes with intra- and intermolecular cooperativity specific of the a transition. They will be called a transition motions, in order distinguish them from the /3 transition motions analysed in [ 1],... 

Hubbel, W. L., Cafiso, D. S., and Altenbach, C. (2000). Identifying conformational changes with site-directed spin labeling. Nat. Struct. Biol. 7, 735—741. 

Molecular modeling studies correlate very well with the experimental observations [138]. The plot of the computed interaction energies versus lipophilicity mns parallel to the plot of 1/T2 versus lipophilicity (Figure 3.40). The result confirms the proposed conformational change with lengthening of the N-alkyl groups of the benzy-lamines. It is an example of the general model proposed by Herbette and coworkers... 

Onufriev A, Bashford D, Case DA (2004) Exploring protein native states and large-scale conformational changes with a modified generalized born model. Proteins 55(2) 383-394... 

An alternative control would be direct interaction between the electron carrier protein and the protein exchanger, but it is not clear that there is sufficient oxidase available to interact by direct conformational change with the exchanger molecules. 

Quantum mechanical calculations are also useful in predicting minimum energy conformations of chromophores and for predicting properties such as dipole moments. Calculated dipole moments are shown for several chromophores in Table 4. Such calculations are particularly useful in understanding how chromophore molecular conformation changes with addition of substituents. 

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