Ligand binding reaction

The chemistry of other synthetic corrinoids is also reviewed with special attention to their preparation procedures and axial ligand binding reactions. 

S. Itoh, D. J. Livingston, M. A. Navia, J. A. Thomson, and K. P. Wilson, Proc. Natl. Acad. Sci. U.S.A., 91, 1964 (1994). Enthalpy of Hydrogen-Bond Formation in a Protein-Ligand Binding Reaction. 

Kinetic traces acquired under pseudo-first-order conditions can be fitted to exponential functions, and the observed rate constants, kobs, can be calculated. The second-order rate constants can be obtained from the slopes of the linear plots of kobs versus [hgand] (e.g. the ligand-binding reactions). The activation parameters can be determined through a systematic variation of temperature and pressure. The activation enthalpies and entropies, AH and A5, are calculated using the Eyring equation (1), and the volumes of activation, AV, calculated from the slope of In kobs versus pressure (under certain conditions). 

Heterogeneity in the kinetic states of signaling molecules was also found in ligand binding reactions in chemotaxing Dictyostelium cells [45]. Dictyostelium cells exhibit chemotaxis in response to cyclic adenosine 3, 5 -monophosphate (cAMP). Dictyostelium cells move randomly in the absence of a cAMP concentration gradient. In the presence of a gradient, however, movement is... 

In the past, similar bidispersed systems have been investigated and modeled in the catalyst deactivation area (5-7). However, modeling of immobilized affinity adsorbent beads is more complex due to the non-linearity introduced by the rapid ligand binding reaction which is dependent on the product concentration. 

Conformational changes are frequently invoked to describe biochemical mechanisms qualitatively. With the surface free energy model, it is possible to evaluate the energetic consequences of conformational changes in proteins. We have done this for the ligand-binding reactions of hemoglobin (8). 

Totani K, lizuka T, Shimada H, Makino R, Ishimura Y (1983) Proton coupling in the ligand-binding reaction of ferric cytochrome P-450 from Pseudomonas putida. Arch Biochem Biophys 222 207-215... 

From the examples that I have discussed, it is clear that the internal motions of macromolecules are intimately involved in ligand binding reactions. It is of interest, therefore, to examine the general characteristics of these internal motions. This can be done theoretically by means of molecular and harmonic dynamic techniques. 

It can be seen that yeast and the plant peroxidases which all contain ferriprotoporphyrin IX behave similarly with a consistent trend in all results. Lactoperoxidase with a heme group of unknown structure behaves much differently in its ligand binding reactions and metmyoglobin (which also contains ferriprotoporphyrin IX) cannot be fit into any peroxidase pattern. In all cases for the peroxidases it is the electrically neutral (protonated) form of the ligand which reacts (see Appendix). For the yeast and plant peroxidases the results for H2O2, HF and HN3 indicate that a dissociative... 

Connelly, P.R., Aldape, RA., Bruzzese, F.J., et al (1994) Enthalpy of hydrogen bond formation in a protein-ligand binding reaction. Proceeding of the National Academy of Sciences of the United States of America, 91,1964-1968. 

IV. MYOGLOBIN ELECTRON TRANSFER AND LIGAND-BINDING REACTIONS... 

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