Synthesis and biochemical evaluation of 2'-deoxy-lin-benzoadenosine phosphates

Abstract

2'-Deoxy-lin-benzoadenosine has been synthesized via reductive deoxygenation of 2-(beta-D-ribofuranosyl)-8-(methylthio)imidazo[4,5-g]quinazoline. The 5'-mono-, 5'-di-, and 5'-triphosphates have been prepared by chemical and/or enzymatic methods. The 5'-diphosphate was found to be a substrate for phosphorylation by pyruvate kinase and was compared with various natural and extended substrates in kinetic assays. When 2'-deoxy-lin-benzoadenosine 5'-triphosphate was tested in a nick-translation experiment with Escherichia coli DNA polymerase I, a very low level of 32P incorporation from [alpha-32P]TTP into poly[d(AT)] was observed. Nearest-neighbor analysis indicated that the analogue was not significantly incorporated into internal positions in the polymer. In DNA-sequencing reactions, the analogue caused chain termination at adensine residues, although termination was less uniform and less efficient than that with 2',3'-dideoxy-ATP. These experiments show that lin-benzoadenine can form a widened Watson-Crick base pair with thymine. They strongly suggest, though they do not prove, that the enzyme is able to attach the analogue to DNA.

Replacement of Thymidine by a Modified Base in the Escherichia coli Genome

“…Leonard and coworkers developed several extended purines to investigate enzyme recognition and base pairing. 5–7 Benner and coworkers have generated an isoG-isoC base pair (Figure 1A) and examined its in vitro replication, transcription and translation reactions. 8–10 They further developed an unnatural P B -Z B base pair (Figure 1B) that functions in PCR with high efficiency.…”

Preparation of pyridine-stretched 2'-deoxyhypoxanthosine phosphoramidite

“…[1][2][3][4] Later, the 2-deoxy derivative 3 was prepared ( Figure 1). 5 Recently, benzo homologation of various nucleosides and their oligomerisation has culminated in the realisation of complete series' of benzene-stretched xDNA [6][7][8] and yDNA 9 analogues that are orthogonal to natural DNA. The limits to size expansion have continued to be explored through the study of base-pairs formed between purines and their naphtho-homologated complements in "double-wide DNA" (yyDNA).…”

Künstliche genetische Systeme bestehend aus vergrößerten Basenpaaren

“…[10] Letzteres wurde zum Testen von ATPabhängigen Enzymen verwendet, [11] aber nicht innerhalb von DNA untersucht (Leonard betrachtete es als zu groß für DNA). Synthese, Eigenschaften und Anwendungen von vergrçßerten Nukleobasen in DNA 2.1.…”