* This stabilization does not seem to caused by the formation of specific ion pairs or ion networks, but by a dramatic change in the electrostatic potential. In Bc-Csp Arg3, the general stabilizing effects of single charged residues, possibly by long range electrostatic interactions.

* The extra thermostability of Bc-Csp apparently arose in a very simple manner from changes at only two position, 3 and 66.

* It has been known for some time that the proteins from thermaophilic organisms have an increased number of charged AA. In the high temperature condition, these proteins' stability would be maintained when a dielectric constant getting lower.

When 0 oC H2O D=80; 25 oC D=78; 100 oC D=55

* These results are very encouraging for the development of strategies to increase stability by protein engineering.