Biological systems binding proteins

The choice of a solvent model for the hydrophobic interaction. Obviously the selectivity of the biological system cannot be modeled by a solvent. However, solvents can be chosen to model the partial desolvation observed in protein-protein interactions (see above) because there is a qualitative analogy between water and non-polar solvents and the interaction of small molecules with biological systems. This can be expressed as a quantitative relation between partition coefficients and the binding to biological systems (receptors, proteins, membranes, etc.) It... 

In biological systems many proteins interact specifically with various chemical compounds (78). There is also a less-specific type of interaction by which even denatured proteins can bind miscellaneous nonprotein compounds. Such a phenomenon is often observed in the area of food processing. Most food proteins contain nonprotein impurities such as... 

The most conspicuous use of iron in biological systems is in our blood, where the erythrocytes are filled with the oxygen-binding protein hemoglobin. The red color of blood is due to the iron atom bound to the heme group in hemoglobin. Similar heme-bound iron atoms are present in a number of proteins involved in electron-transfer reactions, notably cytochromes. A chemically more sophisticated use of iron is found in an enzyme, ribo nucleotide reductase, that catalyzes the conversion of ribonucleotides to deoxyribonucleotides, an important step in the synthesis of the building blocks of DNA. 

Essentially as a result of its ability to bind to basic sites, heparin interacts with many proteins.398 Although most of these interactions (such as that with protamine, a basic protein frequently used to neutralize heparin399) are probably not of biological significance, binding to plasma proteins and to proteins exposed on the surface of endothelial cells has an important influence on the circulation system. 

In a real biological system, DNA is mostly surrounded by many proteins. Protein binding to DNA involves a number of hydrogen bonds and electrostatic contacts between two biopolymers, and induces not only structural deviation from the typical B-form structure, but also electronic perturbation of the -stacked array of base pairs. We tackled the electronic effects of protein binding on the efficiency of hole transport by using a restriction en-... 

There is a protein, metallothionine, which is found in kidney and which binds cadmium and zinc very effectively. This may well be related to the bacterial protein. We see that biological systems have developed highly selective ways of countering the influence of poisonous metals. The protection involves the interaction between a selected protein and a given metal. We can now return to platinum chemistry. 

The application of magnetic resonance techniques to biological systems is a relatively new approach for the study of macromolecules. In this review we have presented the different approaches which have been made to study Bi2-enzymes. Clearly some progress has been made particularly from the application of ESR to a study of the enzymes ethanolamine ammonia-lyase and ribonucleotide reductase. Although 13C NMR is well in its developmental stages it is obvious that this technique will prove to be very useful for the examination of coenzyme-enzyme interactions. Studies of how corrinoids bind in enzymes and how sulfhydryl containing proteins are involved in enzyme catalysis comprise two major problems which must be overcome before realistic mechanisms can be presented for this group of enzymes. 

Sacchettini, J.C. and Gordon, J.I. (1993) Rat intestinal fatty acid binding protein a model system for analyzing the forces that can bind fatty acids to proteins. Journal of Biological Chemistry 268, 18399—18402. 

Table XI (346-390) lists a number of calcium-binding proteins and indicates very succinctly their role in biological systems. This table both illustrates the range of functions of calcium-binding proteins and serves to introduce those which appear subsequently in this chapter. The structures and functions of particularly important calcium-binding proteins such as calmodulin, parvalbumin, and troponin C are described in standard texts on biochemistry. The minimal Table XI entry for the particularly important calmodulins is amplified in the next paragraph. Table XI provides a sprinkling of references to enable readers to gain entry into the literature, for these and for most of the less-familiar species.

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