Chemistry Reference
In-Depth Information
Figure 7.14 Preparation of recombinant plasmid DNA using Ce(
IV
)/EDTA
and pcPNA additives.
that of foreign DNA (DNA
(1)
/DNA
(2)
duplex), is picked up and selectively incorporated
into the recombinant DNA. Furthermore, recombinant plasmid DNA has been suc-
cessfully prepared using the present artificial restriction enzymes (Figure 7.14). Since
pcPNA can invade DNAs of various sequences, these artificial restriction enzymes
should be applicable to the manipulation of still longer DNAs.
7.7
Conclusion
The preparation of artificial restriction enzymes has been one of the most attractive
themes for chemists and biochemists, since they are essential for manipulating huge
DNA in future biotechnology. As described in this chapter, useful tools for site-selec-
tive scission of either single-stranded or double-stranded DNA are now in hand. The
key factor for the molecular design of these artificial enzymes is preferential hydrolysis
of single-stranded portions by the Ce(
IV
)/EDTA complex over double-stranded por-
tions. Accordingly, substrate DNA is site-selectively hydrolyzed when a gap-structure
(or its relevance) is formed at a predetermined position by using appropriate DNA or
PNA additives. The sequences and lengths of these additives can be freely chosen, and
thus these systems are applicable to DNA substrates of any length and sequence.
