Site Directed after

In a linear crystal in which the sites are separated by a unit distance + a, each individual value of x, can be +a or -a. As the jumps take place with an equal probability in both directions, after n jumps the total displacement in any one walk may have any value between zero and + na. 

Unlike the AAOs, whose very name implies a breadth of substrate specificity, the aaDHs tend to be rather more specific and are each named after their optimal amino acid substrate. In particular, the archetype in this enzyme family, GDH, shows poor activity with most substrates other than glutamate. However, the availability of X-ray crystallographic structures for several aaDHs ° has opened the door to site-directed mutagenesis and altered substrate specificities. " ... 

The rate of absorption of a local anesthetic into the bloodstream is affected by the dose administered, the vascularity at the site of injection, and the specific physicochemical properties of the drug itself. Local anesthetics gain entrance into the bloodstream by absorption from the injection site, direct intravenous injection, or absorption across the mucous membranes after topical application. Direct intravascular injection occurs accidentally when the needle used for infiltration of the local anesthetic lies within a blood vessel, or it occurs intentionally when Udocaine is used for the control of cardiac arrhythmias. 

Erickson, B.D. Mondello, F.J. (1993). Enhanced biodegradation of polychlorinated biphenyls after site-directed mutagenesis of a biphenyl dioxygenase gene. Applied and Environmental Microbiology, 59, 3858-62. 

---