Photolithographic coating of polymers on DNA as an approach for construction of nano-structures

We synthesized poly(N-isopropylacrylamide) terminated with psoralen. Photo- induced reaction between DNA and the psoralen end group resulted in the gra fting of poly(N-isopropylacrylamide) on double-stranded DNA. On the other h and, binding efficiency of DNA binding proteins such as restriction endonuc leases to the DNA decreased significantly with increasing degree of polymer modification: At a certain level of polymer introduction, DNA was revealed to be practically 'jacketed'. Lithography was attempted to this grafting p rocedure. We found that pre-incubation of a restriction endonuclease EcoRI with DNA resulted in selective preservation of its binding site from polyme r modification. The application of this technique would allow us facile met hods to construct a precisely regulated nanoscale architecture. (C) 1998 El sevier Science Limited. All rights reserved.