Minimum distance approach acids

Table VIII. Values of Slope, /3 (Eq. 31), the Anionic Contribution to Minimum Distance of Approach (r ) and the Minimum Distance Approach (r) for a Number of Acids (25°C)°...

A) A distance matrix was constructed from the inferred amino acid sequences using a Poisson correction for multiple hits and the tree constructed using the minimum evolution approach. Five hundred bootstrap resamplings were carried out. Branches with bootstrap support values less than 50% are indicated with an asterisk. 

The 1—4 distance and the 1—B or 1—N distance were the only variables. [4] and [5] are separated by a considerable barrier. In the case of the base, three minima are present, corresponding to isomers [4] and [5] and the adduct [9]. In the case of the acid, only one minimum, that corresponding to the adduct [5], is present, since it is possible to go from [4] and [5] to [5] without any barrier. This means that on approach of BH3, the two species [4] and [5] merge into the zwitterion [5], i.e. acid catalyzes the isomer interconversion, while base does not. 

Fig. 4 The elastic network model approach. A folded protein (left) is reduced to a minimal set of beads representative of its amino acid sequence (centre), Beads are connected to each other (right) through a model pair-potential with global minimum at each pair s distance in the native structure.

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