Targeting specificity

The ideal plant growth regulator should leave no harmful persistent residue in a finished product or crop and the paradigm compounds are ones that have high specific activity, are target specific, and are environmentally biodegradable. 

Future development of SAM-based analytical technology requires expansion of the size and shape selectivity of template stmctures, as well as introduction of advanced chemical and optical gating mechanisms. An important contribution of SAMs is in miniaturization of analytical instmmentation. This use may in turn have considerable importance in the biomedical analytical area, where miniature analytical probes will be introduced into the body and target-specific organs or even cell clusters. Advances in high resolution spatial patterning of SAMs open the way for such technologies (268,352). 

Little attempt has been made to develop drugs targeted specifically to white adipose tissue and the production of adipokines. It is likely, however, that there will be an increasing emphasis on this approach to the pharmacological treatment of obesity-related diseases, given the current views on the centrality of the adipokines to these disorders. It is, of course, the diseases that obesity leads to, rather than obesity itself, that constitute the main medical challenge. 

Grimson A, Earh KK, Johnston WK, Garrett-Engele P, Lim LP, Bartel DP (2007) MicroRNA targeting specificity in mammals determinants beyond seed pairing. Mol Cell 27 91-105... 

With respect to toxins which target specific sites, insight can be obtained from the anomolies that are observed. For example, both puffer fish and tetrodotoxin-containing crabs (96) are insensitive to tetrodotoxin. The investigation of such insensitivities can provide information about membrane channels and their toxin binding sites. 

Some of the best investigated anti-nutrients are the enzyme inhibitors present in legumes and other plants. The Bowman-Birk and the Kunitz inhibitors of trypsin and other proteases are among the best characterized. In contrast to the non-specific and widespread influences of tannins and lectins (Carmona, 1996), the Bowman-Birk, Kunitz and other such inhibitors target specific enzymes. Corresponding with this, proteases and other digestive enzymes vary in sensitivity to the different inhibitors. 

Once several target methods employing, e.g., LC/MS/MS techniques have been combined, a multi-residue method will evolve which includes the DEC S19 extraction procedures in combination with the generally applicable GPC cleanup and requires automatic multiple injections to circumvent the limitations of the limited HPLC peak capacity and the target-specific MS/MS methods. 

Prior to a detailed analysis of target specific assays, it would be prudent to review some of the homogeneous technologies that have recently become commercially available. The last 10 years have seen a substantial increase in the variety of techniques available for measuring biochemical activity. A few of the more popular techniques will be reviewed here. 

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