Biological selectivity

Weber, B.H. (1998). Emergence of life and biological selection from the perspective of complex systems dynamics. In Van de Vigver et al. (eds.). Evolutionary Systems. Kluwer Academic Publishers, pp. 59-66... 

In recent years the major goal of medicine has been to find new drugs or pro-drugs to improve efficacy and biological selectivity towards specific diseases. 

Romanczuk H, Galer CE, Zabner J, et al. Modihcation of an adenoviral vector with biologically selected peptides a novel strategy for gene delivery to cells of choice. Hum Gene Ther 1999 10(16) 2615-2626. 

As with the cyclo retro isomers, these studies have shown that there may be more than one peptide backbone conformation which can produce similar side chain topography. The N -methyl lysine analogs have also further confirmed that the n -H of lysine has no important role in receptor binding or conformational stabilization. These compounds did not, however, provide any advantage over 3 in biological selectivity or duration of action. 

However, new types of radiation continue to be explored with the aim of improving the physical selectivity, the radiobiological differential effect, or both. In this context, the role of fast neutrons with their biological selectivity in selected cancer sites and of protons with their superb physical selectivity will be reviewed. 

The possible factors involved in the biological selectivity towards metal ions have been considered by Frausto da Silva and Williams3 and by Kustin et al.4 In terms of thermodynamic selectivity a useful formalism for the uptake of any metal ion from a multimetal system is the quotient A Cm, where Km is a relative stability constant and Cm is the concentration of the metal ion. However, as these authors point out,3 a combination of both thermodynamic and kinetic properties must be considered. An appreciation of kinetic factors is often absent in this field, but must be of prime consideration in chelate exchange reactions and in the final irreversible step of metal ion insertion to form the metalloenzymes. 

The chemistry of transport systems has three main goals to design transport effectors, to devise transport processes, and to investigate their applications in chemistry and in biology. Selective membrane permeability may be induced either by carrier molecules or by transmembrane channels (Fig. 10). 

A comparable strategy is applied to obtain compounds with a pronounced biological selectivity. By treatment of a porous NH3+-containing polypropylene membrane with the sulfate of dextran, a material for convenient removal... 

Glycan specificity governed by multivalency provides biological selectivity... 

The newest generation of electrochemical-based biological detection devices is the biosensors. These devices combine the high spatial and temporal resolution of an electrochemical microsensor with a biologically selective recognition element. In... 

The drug did that and nothing else, either by true biological selectivity or by selective targeted delivery... 

Williams (150) has addressed this question in his 1981 Royal Society Bakerian Lecture on Natural Selection of the Chemical Elements. This describes how the biological selection of elements and their chemical properties are related. Williams has also given a detailed account (51) of the chemical basis of the uptake of elements by biological systems, and described (130) the chemistry that may occur in the specific case of aluminum. Based on this analysis he suggests a major problem with acid rain is the increased biological availability of aluminum. 

Biological Selectivity and sensitivity of immobilized aptamers Nature and length of covalent linker for immobilization 49... 

Biological Selection of coupling reagents for immobilization of antibodies 121... 

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