Metal nanocluster-modified nucleotides
Organic Molecular Chemistry - Synthesis and Characterisation
Final Report Abstract
The capability of DNA polymerases to accept modified 2’-deoxynucleoside triphosphates (dNTPs) is exploited in many important biotechnological applications. Moreover, utilizing the intrinsic properties of DNA in combination with chemically introduced functionalities provides an entry to new classes of nucleic acids-based hybrid materials. In most cases the dNTP modifications were introduced to the nucleobase. Thereby, the C5 position of pyrimidines and the C7 of 7-deazapurines were identified as best suited for the introduction of modifications without compromising DNA polymerase activity. In addition, these modifications are well accommodated into the major groove of DNA without perturbing the DNA structure. Noble metal-based nano particles (NP), e.g., those derived from Au, have found numerous applications ranging from Material Sciences to Life Sciences. This is due to their inherent and unique features like optical properties that depend on the size of the NP. Despite the impressive properties of metal NPs, these have poorly exploited as modification for dNTPs and subsequently as substrate for DNA polymerases. This subject was addressed in this project. We could synthesize NP-modified dNTPs. For the synthesis of the NP-modified dNTPs, the usage of an enzyme-modified dNTP was essential. As bait enzyme we used horse radish peroxidase (HRP) since previous studies demonstrated that these conjugates are suitable substrates for DNA polymerases. Much to our delight, we could indeed show that they are substrates for several DNA polymerases despite their size exceeding the size of the natural substrates by several magnitudes. The proficiency of DNA polymerases to incorporate NP-modified nucleotides into DNA is a first step for future applications.
