Recognition partners

Information may be stored in the architecture of the receptor, in its binding sites, and in the ligand layer surrounding the bound substrate such as specified in Table 1. It is read out at the rate of formation and dissociation of the receptor—substrate complex (14). The success of this approach to molecular recognition ties in estabUshing a precise complementarity between the associating partners, ie, optimal information content of a receptor with respect to a given substrate. 

Possible explanations for this difference in behavior may involve complex formation between the nitrobenzenes and ammonia, reaction in a vibrationally excited level of the ground state, or, preferably, a recognition that in these cases the reaction partner is an electrically neutral species present in high... 

On the whole, it seems that humans are able to recognize their own body odour and women mostly tend to assess it as pleasant and men mostly as unpleasant. The significant results from experiments dealing with the question of the sexual partner s body odour recognition indicate that humans can learn their partner s olfactory cues, probably through their mutual intimacy. 

Successful reproductive behavior relies on the ability to identify and approach appropriate mating partners within the environment. Critically, mate recognition requires identifying species and sex characteristics of possible mates. As in many mammalian species, rodents use odor cues as the primary mechanism for mate recognition (Johnston 1983). Thus, sexually mature rodents typically display strong behavioral preferences for conspecific odors from opposite-sex individuals compared to odors from the same-sex or heterospecific individuals (Johnston 1983). 

One may use the stronger term chirality discrimination when a substantial suppression of one intermolecular diastereomer with respect to the other occurs. This requires multiple strong interactions between the two molecular units and therefore more than simple monofunctional alcohols. Some examples where one of the molecules involved is a chiral alkanol are reported in Refs. 112 and 119 121. Pronounced cases of higher-order chirality discrimination have been observed in clusters of hydroxy esters such as methyl lactate tetramers [122] and in protonated serine octamers [15,123,124]. The presence of an alcohol functionality appears to be favorable for accentuated chirality discrimination phenomena even in these complex systems [113,123,125,126]. Because the border between chirality recognition and discrimination is quite undefined, it is suggested that the two may be used synonymously whenever both molecular partners are permanently chiral [127]. 

The fundamental behaviour of stationary phase materials is related to their solubility-interaction properties. A hydrophobic phase acts as a partner to a hydrophobic interaction. An ionic phase acts as a partner for ion-ion interactions, and surface metal ions as a partner for ligand complex formation. A chiral phase partners chiral recognition, and specific three-dimensional phases partner affinity interactions. 

In biological systems, electron transfer kinetics are determined by many factors of different physical origin. This is especially true in the case of a bimolecular reaction, since the rate expression then involves the formation constant Kf of the transient bimolecular complex as well as the rate of the intracomplex transfer [4]. The elucidation of the factors that influence the value of Kf in redox reactions between two proteins, or between a protein and organic or inorganic complexes, has been the subject of many experimental studies, and some of them are presented in this volume. The complexation step is essential in ensuring specific recognition between physiological partners. However, it is not considered in the present chapter, which deals with the intramolecular or intracomplex steps which are the direct concern of electron transfer theories. 

Dougan, D. a., Mogk, a., Zeth, K., Turgay, K., and Bukau, B. AAA+ proteins and substrate recognition, it all depends on their partner in crime. FEBS Lett 2002, 529, 6-10. 

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