Shape rational pocket

Figure 252. Schematic representation of two extreme pocket shapes, (a) Half circle, no briquette production possible due to release difficulties, (b) Rationally shaped pocket (tear drop)...

During these experiments the randomized residues were still restricted to the original set of positions chosen within the four loops. However, from recent structural analyses (see Section 8.4) it appeared that there are additional, so far non-mutated amino acids that contribute to the shape of the ligand pocket and may therefore govern affinity and specificity for the steroids. Thus, future improvement in molecular recognition by this engineered lipocalin may be guided by rational principles. 

The lack of resolution by which mechanism the osmylation proceeds has resulted in two models to rationalize the face selectivity of the AD reaction. The commonality of these two predictive models resides in the basic principle that a chiral binding pocket is formed from the ligand s aromatic groups. However, the shape and location of this pocket in the complex is not identical. 

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